diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 880f5cb..5133918 100755
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,7 +17,15 @@ jobs:
       - uses: actions/setup-java@v4.6.0
         with:
           distribution: "temurin"
-          java-version: "23-ea"
+          java-version: "21"
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: gradle-
 
       - name: Checkout
         uses: actions/checkout@v4.2.2
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 78d4045..5967de2 100755
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -4,6 +4,10 @@ on:
   schedule:
     - cron: "0 16 * * *"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check:
     permissions: write-all
@@ -37,7 +41,9 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          gh run list -L400 --json databaseId -q '.[].databaseId' | tail -n+10 | xargs -IID gh api "repos/$GITHUB_REPOSITORY/actions/runs/ID" -X DELETE || :
+          gh run list --workflow "${{ github.workflow }}" -L400 --json databaseId -q '.[].databaseId' | 
+          tail -n+10 | 
+          xargs -I{} gh api "repos/${{ github.repository }}/actions/runs/{}" -X DELETE || true
 
     outputs:
       SHOULD_BUILD: ${{ steps.should_build.outputs.SHOULD_BUILD }}
@@ -45,6 +51,6 @@ jobs:
   build:
     permissions: write-all
     needs: check
+    if: needs.check.outputs.SHOULD_BUILD == '1'
     uses: ./.github/workflows/build.yml
-    if: ${{ needs.check.outputs.SHOULD_BUILD == 1 }}
     secrets: inherit