Set JDK21 as the baseline for the 3.0 major version

Signed-off-by: Andrew Ross <andrross@amazon.com>

.github/workflows/check.yml

@@ -11,7 +11,7 @@ jobs:
     needs: Get-CI-Image-Tag
     strategy:
       matrix:
-        java: [ 11, 17, 21 ]
+        java: [ 21 ]
     if: github.repository == 'opensearch-project/custom-codecs'
     runs-on: ubuntu-latest
     container:
@@ -38,7 +38,7 @@ jobs:
     if: github.repository == 'opensearch-project/custom-codecs'
     strategy:
       matrix:
-        java: [ 11, 17, 21 ]
+        java: [ 21 ]
         os: [windows-latest, macos-13]
     runs-on: ${{ matrix.os }}
     steps:

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/setup-java@v4
         with:
           distribution: temurin # Temurin is a distribution of adoptium
-          java-version: 17
+          java-version: 21
 
       - name: Checkout custom-codecs Repo
         uses: actions/checkout@v4

.github/workflows/publish-maven-snapshots.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/setup-java@v3
         with:
           distribution: temurin
-          java-version: 11
+          java-version: 21
       - uses: actions/checkout@v3
       - uses: aws-actions/configure-aws-credentials@v1
         with:

build.gradle

@@ -78,8 +78,8 @@ allprojects {
   }
 
   java {
-      targetCompatibility = JavaVersion.VERSION_11
-      sourceCompatibility = JavaVersion.VERSION_11
+      targetCompatibility = JavaVersion.VERSION_21
+      sourceCompatibility = JavaVersion.VERSION_21
   }
 }