chore(build): Compile with a JDK 21 toolchain and upgrade Mockito and Error Prone (#6242)

* build: Switch to JDK 21 and upgrade Mockito, Robolectric and Error Prone

* build: Compile tests for JDK 21 and fix buildSrc JVM target

* build: Compile with a JDK 21 toolchain from a build-logic convention plugin

* docs(kafka): Explain the explicit double cast at the latency call site

* build: Compile the samples and their tests with the toolchain JDK

* Format code

* build: Drop the now-unused JvmTarget imports from the samples

* build: Clarify the jvm-targets plugin comments and rename its helper

* build: Require JDK 21 to run Gradle again

* build: Keep the Spring Boot 2 sample apps on their published bytecode level

* ci: Drop the stale Java version from the build job name

* build: Keep Robolectric at 4.15 and leave its test environment untouched

* build: Move the Java 8 release pin into the jvm-targets convention plugin

* build: Drop the Error Prone and NullAway code fixes, they move to their own PR

* ci: Drop the stale Java version from the build job name

* fix(core): Suppress the new Error Prone and javac 21 findings in the sentry module

* fix(core): Resolve the remaining Error Prone and javac 21 findings in the sentry module

* build: Move the JDK and bytecode level decisions into the io.sentry.compilation plugin

* Address PR comments

* test(android): Make the flush timeout verifies match the real log call

* chore(core): Reword the JDK 21 suppression comments

* build: Keep only the javac unit test targets inside afterEvaluate

* build: Drop afterEvaluate, pin the Kotlin API level and rename the convention plugin

* Fix JDK 21 findings in sentry-android-core (#6261)

Fix JDK 21 findings in sentry-android-core

* Fix JDK 21 findings in the Spring modules (#6260)

* Fix JDK 21 findings in the JVM integrations (#6259)

* fix multiplatform target compilations

---------

Co-authored-by: Sentry Github Bot <bot+github-bot@sentry.io>

Author: markushi

.github/workflows/agp-matrix.yml

@@ -36,7 +36,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/build.yml

@@ -12,7 +12,7 @@ concurrency:
 jobs:
   build:
     # Job name is a required status check in the main branch ruleset; keep it stable.
-    name: Build Job ubuntu-latest - Java 17
+    name: Build Job ubuntu-latest
     runs-on: ubuntu-latest
 
     env:
@@ -29,7 +29,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       # Workaround for https://github.com/gradle/actions/issues/21 to use config cache
       - name: Cache buildSrc

.github/workflows/codeql-analysis.yml

@@ -28,7 +28,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/enforce-license-compliance.yml

@@ -17,7 +17,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Checkout
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/format-code.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/generate-javadocs.yml

@@ -17,7 +17,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/integration-tests-macrobenchmark.yml

@@ -26,7 +26,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/integration-tests-size.yml

@@ -26,7 +26,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: "temurin"
-          java-version: "17"
+          java-version: "21"
 
       # Workaround for https://github.com/gradle/actions/issues/21 to use config cache
       - name: Cache buildSrc

.github/workflows/integration-tests-ui-critical.yml

@@ -33,7 +33,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0

.github/workflows/integration-tests-ui.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0