Bump up Gravatar to 2.0.0

[pinarol]

Fixes #

Gravatar SDK has a new release(yaay 🎉 ). This PR makes necessary updates to use it.

To test:

Smoke test scenarios in #22543. The avatars should load fine. Uploading a new avatar should also work fine.

Regression Notes

1. Potential unintended areas of impact

All avatars in the app.

2. What I did to test those areas of impact (or what existing automated tests I relied on)

I documented the use cases in #22543 and tested those.

4. What automated tests I added (or what prevented me from doing so)

No new automated tests were added since we aren't adding new functionality.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Testing checklist:

• WordPress.com sites and self-hosted Jetpack sites.
• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• VoiceOver.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• iPhone and iPad.
• Multi-tasking: Split view and Slide over. (iPad)

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr23320-1a5edd1
	Version	25.1
	Bundle ID	org.wordpress.alpha
	Commit	1a5edd1
	App Center Build	WPiOS - One-Offs #10151

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr23320-1a5edd1
	Version	25.1
	Bundle ID	com.jetpack.alpha
	Commit	1a5edd1
	App Center Build	jetpack-installable-builds #9199

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[etoledom]

Testing together with Automattic/Gravatar-SDK-iOS#276 , things look good to me.
I'd say It's ready to move to formal review 👍

[pinarol]

Ready to review.

[etoledom]

Looks good!