ci: use reusable workflow for semgrep (#886)

Updated the build-test-release workflow to use
[sast-scan](https://github.com/splunk/sast-scanning) owned by product
security team instead of using custom implementation.
Ref: https://splunk.atlassian.net/browse/ADDON-72309

Author: dvarasani-crest

.github/workflows/build-test-release.yml

@@ -62,14 +62,9 @@ jobs:
       - uses: pre-commit/[email protected]
 
   semgrep:
-    runs-on: ubuntu-latest
-    name: security-sast-semgrep
-    steps:
-      - uses: actions/checkout@v4
-      - id: semgrep
-        uses: semgrep/semgrep-action@v1
-        with:
-          publishToken: ${{ secrets.SEMGREP_PUBLISH_TOKEN }}
+    uses: splunk/sast-scanning/.github/workflows/sast-scan.yml@main
+    secrets:
+      SEMGREP_KEY: ${{ secrets.SEMGREP_PUBLISH_TOKEN }}
 
   test-splunk-unit:
     runs-on: ubuntu-latest