Clean up secrets (#1921)

Summary:
See this being done elsewhere. I don't think it's necessary but why not?

Pull Request resolved: https://github.com/facebook/flipper/pull/1921

Test Plan: eyes

Reviewed By: jknoxville

Differential Revision: D26427191

Pulled By: passy

fbshipit-source-id: 80823bf50d6416d29d54c82cef433650c1451ac0

.github/workflows/publish-android.yml

@@ -40,6 +40,9 @@ jobs:
       env:
         SONATYPE_NEXUS_PASSWORD: ${{ secrets.SONATYPE_NEXUS_PASSWORD }}
         SONATYPE_NEXUS_USERNAME: ${{ secrets.SONATYPE_NEXUS_USERNAME }}
+    - name: Clean secrets
+      if: always()
+      run: rm /tmp/secring.gpg
     - name: Rename apk
       run: mv android/sample/build/outputs/apk/debug/sample-debug.apk SampleApp-android.apk
     - name: Attach sample APK to release