Replace deprecated ::set-output in the workflows

Author: DavideD

.github/workflows/build.yml

@@ -86,7 +86,7 @@ jobs:
       - name: Get year/month for cache key
         id: get-date
         run: |
-          echo "::set-output name=yearmonth::$(/bin/date -u "+%Y-%m")"
+          echo "yearmonth=$(/bin/date -u '+%Y-%m')" >> "$GITHUB_OUTPUT"
         shell: bash
       - name: Cache Gradle downloads
         uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
@@ -128,7 +128,7 @@ jobs:
       - name: Get year/month for cache key
         id: get-date
         run: |
-          echo "::set-output name=yearmonth::$(/bin/date -u "+%Y-%m")"
+          echo "yearmonth=$(/bin/date -u '+%Y-%m')" >> "$GITHUB_OUTPUT"
         shell: bash
       - name: Cache Gradle downloads
         uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
@@ -185,7 +185,7 @@ jobs:
       - name: Get year/month for cache key
         id: get-date
         run: |
-          echo "::set-output name=yearmonth::$(/bin/date -u "+%Y-%m")"
+          echo "yearmonth=$(/bin/date -u '+%Y-%m')" >> "$GITHUB_OUTPUT"
         shell: bash
 
       - name: Generate cache key
@@ -246,7 +246,7 @@ jobs:
           check-latest: true
       - name: Export path to JDK ${{ matrix.java.name }}
         id: testjdk-exportpath
-        run: echo "::set-output name=path::${JAVA_HOME}"
+        run: echo "path=${JAVA_HOME}" >> $GITHUB_OUTPUT
       # Always use JDK 11 to build the main code: that's what we use for releases.
       - name: Set up JDK 11
         uses: actions/setup-java@3a4f6e1af504cf6a31855fa899c6aa5355ba6c12 # v4.7.0
@@ -256,7 +256,7 @@ jobs:
           check-latest: true
       - name: Export path to JDK 11
         id: mainjdk-exportpath
-        run: echo "::set-output name=path::${JAVA_HOME}"
+        run: echo "path=${JAVA_HOME}" >> $GITHUB_OUTPUT
       - name: Display exact version of JDK ${{ matrix.java.name }}
         run: |
           ${{ steps.testjdk-exportpath.outputs.path }}/bin/java -version