chore: bump actions/checkout version in example (#394)

to latest v4 https://github.com/actions/checkout/releases

Author: jazanne

build/metadata/github-actions/README.md

@@ -22,9 +22,9 @@ jobs:
     name: LaunchDarkly Code References
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
-        fetch-depth: 10 # This value must be set if the lookback configuration option is not disabled for find-code-references. Read more: https://github.com/launchdarkly/ld-find-code-refs#searching-for-unused-flags-extinctions
+        fetch-depth: 11 # This value must be set if the lookback configuration option is not disabled for find-code-references. Read more: https://github.com/launchdarkly/ld-find-code-refs#searching-for-unused-flags-extinctions
     - name: LaunchDarkly Code References
       uses: launchdarkly/[email protected]
       with:
@@ -57,9 +57,9 @@ jobs:
     name: LaunchDarkly Code References
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
-        fetch-depth: 10 # This value must be set if the lookback configuration option is not disabled for find-code-references. Read more: https://github.com/launchdarkly/ld-find-code-refs#searching-for-unused-flags-extinctions
+        fetch-depth: 11 # This value must be set if the lookback configuration option is not disabled for find-code-references. Read more: https://github.com/launchdarkly/ld-find-code-refs#searching-for-unused-flags-extinctions
     - name: LaunchDarkly Code References
       uses: launchdarkly/[email protected]
       with: