feat: next release from main branch is 1.26.0 (#10442)

Author: lqiu96

.github/release-please.yml

@@ -11,3 +11,8 @@ branches:
     releaseType: java-backport
     manifest: true
     handleGHRelease: true
+  - primaryBranch: main
+    releaseType: java-backport
+    manifest: true
+    handleGHRelease: true
+    branch: 1.25.x

.github/sync-repo-settings.yaml

@@ -44,6 +44,23 @@ branchProtectionRules:
       - enforcer
       - lint
       - 'Kokoro - Test: Integration'
+  - pattern: 1.25.x
+    isAdminEnforced: true
+    requiredApprovingReviewCount: 1
+    requiresCodeOwnerReviews: true
+    requiresStrictStatusChecks: false
+    requiredStatusCheckContexts:
+      - units (8)
+      - units (11)
+      - units (17)
+      - cla/google
+      - enforcer
+      - lint
+      - OwlBot Post Processor
+      - 'Kokoro - Test: Integration'
+      - 'Kokoro - Test: Java GraalVM Native Image'
+      - 'Kokoro - Test: Java 17 GraalVM Native Image'
+      - header-check
 permissionRules:
   - team: yoshi-admins
     permission: admin