ci: configure the protected branch

.github/workflows/ci.yaml

@@ -1,86 +1,92 @@
-on:
+'on':
   push:
     branches:
-    - main
-  pull_request:
+      - 2.4.x
+  pull_request: null
 name: ci
 jobs:
   units:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [8, 11, 17]
+        java:
+          - 8
+          - 11
+          - 17
     steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: actions/setup-java@v2
-      with:
-        distribution: zulu
-        java-version: ${{matrix.java}}
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: test
+      - uses: actions/checkout@v2
+      - uses: stCarolas/setup-maven@v4
+        with:
+          maven-version: 3.8.1
+      - uses: actions/setup-java@v2
+        with:
+          distribution: zulu
+          java-version: ${{matrix.java}}
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: test
   windows:
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: actions/setup-java@v2
-      with:
-        distribution: zulu
-        java-version: 8
-    - run: java -version
-    - run: .kokoro/build.bat
-      env:
-        JOB_TYPE: test
+      - uses: actions/checkout@v2
+      - uses: stCarolas/setup-maven@v4
+        with:
+          maven-version: 3.8.1
+      - uses: actions/setup-java@v2
+        with:
+          distribution: zulu
+          java-version: 8
+      - run: java -version
+      - run: .kokoro/build.bat
+        env:
+          JOB_TYPE: test
   dependencies:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [8, 11, 17]
+        java:
+          - 8
+          - 11
+          - 17
     steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: actions/setup-java@v2
-      with:
-        distribution: zulu
-        java-version: ${{matrix.java}}
-    - run: java -version
-    - run: .kokoro/dependencies.sh
+      - uses: actions/checkout@v2
+      - uses: stCarolas/setup-maven@v4
+        with:
+          maven-version: 3.8.1
+      - uses: actions/setup-java@v2
+        with:
+          distribution: zulu
+          java-version: ${{matrix.java}}
+      - run: java -version
+      - run: .kokoro/dependencies.sh
   lint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: actions/setup-java@v2
-      with:
-        distribution: zulu
-        java-version: 8
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: lint
+      - uses: actions/checkout@v2
+      - uses: stCarolas/setup-maven@v4
+        with:
+          maven-version: 3.8.1
+      - uses: actions/setup-java@v2
+        with:
+          distribution: zulu
+          java-version: 8
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: lint
   clirr:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: actions/setup-java@v2
-      with:
-        distribution: zulu
-        java-version: 8
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: clirr
+      - uses: actions/checkout@v2
+      - uses: stCarolas/setup-maven@v4
+        with:
+          maven-version: 3.8.1
+      - uses: actions/setup-java@v2
+        with:
+          distribution: zulu
+          java-version: 8
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: clirr

.github/workflows/downstream.yaml

@@ -1,16 +1,18 @@
-on:
+'on':
   push:
     branches:
-      - main
-  pull_request:
+      - 2.4.x
+  pull_request: null
 name: downstream
 jobs:
   dependencies:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        java: [8, 11]
+        java:
+          - 8
+          - 11
         repo:
           - java-bigquery
           - java-bigqueryconnection

.github/workflows/upper-bound-check.yaml

@@ -1,8 +1,8 @@
-on:
+'on':
   push:
     branches:
-      - main
-  pull_request:
+      - 2.4.x
+  pull_request: null
 name: upper-bound-check
 jobs:
   upper-bound-check: