chore: fix actions references

Author: chingor13

.github/workflows/hermetic_library_generation.yaml

@@ -37,7 +37,7 @@ jobs:
       with:
         fetch-depth: 0
         token: ${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}
-    - uses: googleapis/sdk-platform-java/.github/scripts@v2.67.0
+    - uses: ./sdk-platform-java/.github/scripts
       if: env.SHOULD_RUN == 'true'
       with:
         base_ref: ${{ github.base_ref }}

.github/workflows/sdk-platform-java-downstream.yaml

@@ -31,7 +31,6 @@ jobs:
       fail-fast: false
       matrix:
         repo:
-          - google-cloud-java
           - java-bigtable
           - java-bigquery
           - java-firestore

.github/workflows/unmanaged_dependency_check.yaml

@@ -14,6 +14,6 @@ jobs:
       shell: bash
       run: mvn install -B -ntp  -T 1C -DskipTests -Dclirr.skip -Dcheckstyle.skip -Denforcer.skip
     - name: Unmanaged dependency check
-      uses: googleapis/sdk-platform-java/java-shared-dependencies/unmanaged-dependency-check@google-cloud-shared-dependencies/v3.57.0
+      uses: ./java-shared-dependencies/unmanaged-dependency-check
       with:
         bom-path: gapic-libraries-bom/pom.xml