Run integration/firestore tests for Firestore code changes

[schmidt-sebastian]

@thebrianchen noticed that one of our integration tests that only runs as part of integration/firestore broke. It looks like this was possible because we did not run those tests as part of Firestore changes.

[google-oss-bot]

Binary Size Report

Affected SDKs

No changes between base commit (ec1471c) and head commit (ef43548).

Test Logs

• Base (ec1471cf): https://github.com/firebase/firebase-js-sdk/actions/runs/118160982
• Head (ef435483): https://github.com/firebase/firebase-js-sdk/actions/runs/118222178

[schmidt-sebastian]

Tested with a change in the firestore package:

Running tests in:
integration/browserify (always runs)
integration/firebase-typings (always runs)
integration/typescript (always runs)
integration/webpack (always runs)
integration/firestore (depends on modified files)
packages/firestore (contains modified files)
packages/firebase (depends on modified files)