fix(ci): Restrict GitHub Actions to main/v1 branches and main repository

Update workflows to ensure they only run on the main repository (google/adk-python)
and target main or v1 branches where applicable. This prevents workflows from
running on forks and restricts merge blocking to main branch.

Co-authored-by: Shangjie Chen <deanchen@google.com>
PiperOrigin-RevId: 940031708

.github/workflows/analyze-releases-for-adk-docs-updates.yml

@@ -37,6 +37,7 @@ on:
 
 jobs:
   analyze-new-release-for-adk-docs-updates:
+    if: github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     permissions:
       contents: read

.github/workflows/block-merge.yml

@@ -16,10 +16,12 @@ name: Do Not Merge on GitHub
 
 on:
   pull_request:
+    branches: [main]
     types: [opened, reopened, synchronize]
 
 jobs:
   block-merge:
+    if: github.repository == 'google/adk-python'
     name: maintainers will submit via Copybara
     runs-on: ubuntu-latest
     steps:

.github/workflows/discussion_answering.yml

@@ -26,8 +26,10 @@ permissions:
 jobs:
   agent-answer-questions:
     if: >-
+      github.repository == 'google/adk-python' && (
       (github.event_name == 'discussion' && github.event.discussion.category.name == 'Q&A') ||
       (github.event_name == 'discussion_comment' && contains(github.event.comment.body, '@adk-bot') && github.event.sender.login != 'adk-bot')
+      )
     runs-on: ubuntu-latest
 
     steps:

.github/workflows/release-cherry-pick.yml

@@ -34,6 +34,7 @@ on:
 
 jobs:
   cherry-pick:
+    if: github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     steps:
       - name: Determine Branch Configurations

.github/workflows/release-cut.yml

@@ -47,6 +47,7 @@ permissions:
 
 jobs:
   cut-or-regenerate:
+    if: github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     steps:
       - name: Determine Branch Configurations

.github/workflows/release-finalize.yml

@@ -29,7 +29,7 @@ permissions:
 
 jobs:
   finalize:
-    if: github.event.pull_request.merged == true
+    if: github.event.pull_request.merged == true && github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     steps:
       - name: Check for release-please PR

.github/workflows/release-publish.yml

@@ -26,6 +26,7 @@ permissions:
 
 jobs:
   publish:
+    if: github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     steps:
       - name: Validate branch

.github/workflows/release-update-adk-web.yaml

@@ -28,6 +28,7 @@ on:
 
 jobs:
   update-frontend:
+    if: github.repository == 'google/adk-python'
     runs-on: ubuntu-latest
     permissions:
       contents: write