Remove SiteIntentQuestionFeatureConfig

[nbradbury]

Fixes #21412

This PR removes the SiteIntentQuestionFeatureConfig feature flag. This flag defaulted to true so it was unnecessary.

There's really nothing to test - a green status from CI should suffice.

[dangermattic]

	1 Warning
:warning:	PR is not assigned to a milestone.

Generated by :no_entry_sign: Danger

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[wpmobilebot]

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

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21426-56d9ae5
	Commit	56d9ae5d07eb43b6c0c3d041446954fce816b1b7
	Direct Download	jetpack-prototype-build-pr21426-56d9ae5.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

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

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21426-56d9ae5
	Commit	56d9ae5d07eb43b6c0c3d041446954fce816b1b7
	Direct Download	wordpress-prototype-build-pr21426-56d9ae5.apk

Note: Google Login is not supported on these builds.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 39.30%. Comparing base (a6145b4) to head (56d9ae5). Report is 110 commits behind head on trunk.

Files with missing lines	Patch %	Lines
...dpress/android/ui/sitecreation/SiteCreationStep.kt	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## trunk #21426 +/- ## ======================================= Coverage 39.30% 39.30% ======================================= Files 2121 2120 -1 Lines 98326 98322 -4 Branches 15233 15232 -1 ======================================= Hits 38649 38649 + Misses 56238 56234 -4 Partials 3439 3439 ```

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