Don't run e2e tests when workflow is triggered by push of tag

In commit 780d6d4 we've turned off uploading of
build artifact to workflow details in case when the workflow is triggered by a
push of tag. Later in we've decided to change conditions of e2e tests execution
to run the tests more frequently. But we've forgotten that we can't run the
tests when workflow is triggered by a tag push, as there is no build artifact
available. Now we're updating the triggers of e2e tests to take that under
consideration.

.github/workflows/build.yml

@@ -115,6 +115,7 @@ jobs:
               - '.env.defaults'
   e2e-tests:
     needs: [build, detect-if-flag-changed]
+    if: ${{ !startsWith(github.ref, 'refs/tags/') }}
     timeout-minutes: 60
     runs-on: ubuntu-latest
     steps: