Fix static-analysis and PHPUnit tests errors

[thelovekesh]

Summary

PHPStan

The latest PHPStan version (1.11.3) is showing a few errors:

[errors]

``` ------ ---------------------------------------------------------------------- Line includes/sanitizers/class-amp-comments-sanitizer.php ------ ---------------------------------------------------------------------- 45 Call to AMP_Base_Sanitizer::init() on a separate line has no effect. ------ ---------------------------------------------------------------------- ------ ---------------------------------------------------------------------- Line includes/sanitizers/class-amp-script-sanitizer.php ------ ---------------------------------------------------------------------- 102 Call to AMP_Base_Sanitizer::init() on a separate line has no effect. ------ ---------------------------------------------------------------------- ------ ---------------------------------------------------------------------- Line includes/sanitizers/class-amp-style-sanitizer.php ------ ---------------------------------------------------------------------- 894 Call to AMP_Base_Sanitizer::init() on a separate line has no effect. ------ ---------------------------------------------------------------------- ```

This PR includes the fix to resolve these static analysis errors.

PHPUnit

A few tests for ReaderThemeSupportFeatures failed due to new changes introduced in theme.json v3. The new versions introduce a new settings.spacing.defaultSpacingSizes property which decides if default space sizing needs to be preferred over the default ones. This PR adds support for this property in reader themes as well. Also see the dev notes for this new change - https://github.com/WordPress/gutenberg/pull/58409#issuecomment-2078077477

Checklist

• [x] My code is tested and passes existing tests.
• [x] My code follows the Engineering Guidelines (updates are often made to the guidelines, check it out periodically).

[github-actions[bot]]

Plugin builds for 59862291e54dec2d343974faefdf7d2301a3ff1f are ready :bellhop_bell:!

• Download development build
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Checksums

# Development build checksums
0ea508aa5064fb79e58f531de24b812c1e55b209c6e0bd1119e4c7c8dc8cfd63 *amp.zip

# Production build checksums
37fa88f69fe8140aff8e5cf5727d81af32857a4ece9d92ebe757a9ab9c9b9acf *amp.zip

[!WARNING] These builds are for testing purposes only and should not be used in production.

[thelovekesh]

Marking as draft now, as I'll be fixing the failing tests in trunk in same PR.

[thelovekesh]

QA Passed ✅

• Static analysis and PHPUnit tests are all 🟢 on the develop branch.
• Regarding the change in ReaderThemeSupportFeatures's theme.json v3:
  • Spacing sizes styles are being included in reader mode.
  • If theme.json version is set to 3, and defaultSpacingSizes is set to true, the default spacing sizes styles are being added as expected in reader mode.