fix: make markdown-lint workflow run on all PRs (#13859)

Co-authored-by: Vincent (Wen Yu) Ge <[email protected]>

Author: webjunkie

.github/workflows/markdown-lint.yml

@@ -2,11 +2,6 @@ name: Markdown Lint
 
 on:
     pull_request:
-        paths:
-            - '**.md'
-            - '**.mdx'
-            - '.markdownlint-cli2.jsonc'
-            - '.github/workflows/markdown-lint.yml'
 
 permissions:
     contents: read
@@ -19,9 +14,26 @@ jobs:
         steps:
             - name: Checkout code
               uses: actions/checkout@v4
+              with:
+                  fetch-depth: 0
+
+            - name: Get changed markdown files
+              id: changed-files
+              uses: tj-actions/changed-files@24d32ffd492484c1d75e0c0b894501ddb9d30d62 # v47
+              with:
+                  files: |
+                      **/*.md
+                      **/*.mdx
+                      .markdownlint-cli2.jsonc
+                      .github/workflows/markdown-lint.yml
 
             - name: Run markdownlint-cli2
-              uses: DavidAnson/markdownlint-cli2-action@v21
+              if: steps.changed-files.outputs.any_changed == 'true'
+              uses: DavidAnson/markdownlint-cli2-action@30a0e04f1870d58f8d717450cc6134995f993c63
               with:
-                  globs: '**/*.{md,mdx}'
+                  globs: ${{ steps.changed-files.outputs.all_changed_files }}
                   config: '.markdownlint-cli2.jsonc'
+
+            - name: Skip if no markdown files changed
+              if: steps.changed-files.outputs.any_changed != 'true'
+              run: echo "No markdown files changed, skipping lint"