Skip upstream-only workflows on forks

Add repository guard (github.repository == 'velero-io/velero') to
workflows that should only run on the upstream repo. This prevents
unnecessary CI runs on forks like openshift/velero where these
workflows either fail due to missing secrets/config or duplicate
fork-specific CI.

Guarded workflows: auto_assign_prs, auto_label_prs,
auto_request_review, e2e-test-kind, nightly-trivy-scan,
pr-changelog-check, pr-codespell, pr-filepath-check,
pr-linter-check, prow-action, rebase, stale-issues.

Intentionally left unguarded: pr-ci-check (useful for contributors
on forks), get-go-version (reusable workflow_call only).

Signed-off-by: Shubham Pampattiwar <spampatt@redhat.com>

.github/workflows/auto_assign_prs.yml

@@ -14,6 +14,7 @@ permissions:
 jobs:
   # Automatically assigns reviewers and owner
   add-reviews:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     steps:
       - name: Set the author of a PR as the assignee

.github/workflows/auto_label_prs.yml

@@ -15,6 +15,7 @@ permissions:
 jobs:
   # Automatically labels PRs based on file globs in the change.
   triage:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/labeler@v5

.github/workflows/auto_request_review.yml

@@ -11,6 +11,7 @@ permissions:
 
 jobs:
   auto-request-review:
+    if: github.repository == 'velero-io/velero'
     name: Auto Request Review
     runs-on: ubuntu-latest
     steps:

.github/workflows/e2e-test-kind.yaml

@@ -17,6 +17,7 @@ jobs:
 
   # Build the Velero CLI and image once for all Kubernetes versions, and cache it so the fan-out workers can get it.
   build:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     needs: get-go-version
     outputs:
@@ -81,6 +82,7 @@ jobs:
   # Create json of k8s versions to test
   # from guide: https://stackoverflow.com/a/65094398/4590470
   setup-test-matrix:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     env:
       GH_TOKEN: ${{ github.token }}
@@ -106,6 +108,7 @@ jobs:
 
   # Run E2E test against all Kubernetes versions on kind
   run-e2e-test:
+    if: github.repository == 'velero-io/velero'
     needs:
       - build
       - setup-test-matrix

.github/workflows/nightly-trivy-scan.yml

@@ -5,6 +5,7 @@ on:
 
 jobs:
   nightly-scan:
+    if: github.repository == 'velero-io/velero'
     name: Trivy nightly scan
     runs-on: ubuntu-latest
     strategy:

.github/workflows/pr-changelog-check.yml

@@ -7,6 +7,7 @@ on:
 jobs:
 
   build:
+    if: github.repository == 'velero-io/velero'
     name: Run Changelog Check
     runs-on: ubuntu-latest
     steps:

.github/workflows/pr-codespell.yml

@@ -3,6 +3,7 @@ on: [pull_request]
 jobs:
 
   codespell:
+    if: github.repository == 'velero-io/velero'
     name: Run Codespell
     runs-on: ubuntu-latest
     steps:

.github/workflows/pr-filepath-check.yml

@@ -3,6 +3,7 @@ on: [pull_request]
 jobs:
 
   filepath-check:
+    if: github.repository == 'velero-io/velero'
     name: Check for invalid characters in file paths
     runs-on: ubuntu-latest
     steps:

.github/workflows/pr-linter-check.yml

@@ -13,6 +13,7 @@ jobs:
       ref: ${{ github.event.pull_request.base.ref }}
 
   build:
+    if: github.repository == 'velero-io/velero'
     name: Run Linter Check
     runs-on: ubuntu-latest
     needs: get-go-version

.github/workflows/prow-action.yml

@@ -11,6 +11,7 @@ permissions:
 
 jobs:
   execute:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     steps:
       - uses: jpmcb/prow-github-actions@v1.1.3

.github/workflows/rebase.yml

@@ -5,7 +5,7 @@ name: Automatic Rebase
 jobs:
   rebase:
     name: Rebase
-    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
+    if: github.repository == 'velero-io/velero' && github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
     runs-on: ubuntu-latest
     steps:
     - name: Checkout the latest code

.github/workflows/stale-issues.yml

@@ -5,6 +5,7 @@ on:
 
 jobs:
   stale:
+    if: github.repository == 'velero-io/velero'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/stale@v10.1.1