Update Cocoapods to 7.11.0 and C++ SDK version to 7.3.0. (firebase#395)

* Update Cocoapods to 7.11.0.

* Update readme file Cocoapods version.

* Update C++ SDK version to 7.3.0.

* Add release notes to readme.

* Update Firestore source dependency to 7.11.0.

* Fix a compiler warning for size_t/int.

* Update iOS integration test OS deployment target to 10.0.

* Pin googletest to release 1.10.0, as master is now broken on iOS.

Merge pull request firebase#364 from firebase/feature/game_loops

Added example implementation of Firebase Test Lab Game Loop library.

Updated release notes and added more info in source comments.

Fix download-artifact version number. (firebase#283)

Fix a linker issue with FIS on Android where the wrong STL was specif…

…ied. (firebase#265)

Merge pull request firebase#261 from firebase/am-installations-gha

Add Installations to the cpp-packaging workflow

Merge remote-tracking branch 'origin/master' into ghm

Merge remote-tracking branch 'origin/master' into ghm

Merge remote-tracking branch 'origin/master' into ghm

Merge remote-tracking branch 'origin/master' into ghm