tests: remove remove_actions() workaround

[ashutoshgautams]

What

Remove temporary workaround for wp-graphql-content-blocks plugin conflicts

Why

The workaround is no longer needed as the underlying issue has been fixed in wp-graphql-content-blocks PR #262

Related Issue(s):

Part of https://github.com/rtCamp/headless/issues/303 (Task sheet)

How

• Removed remove_actions() method and its docblock
• Removed call to $this->remove_actions() in testRequireAutoloader()

Testing Instructions

1. Run PHPUnit tests
2. Verify all tests pass without errors

Screenshots

N/A

Additional Info

N/A

Checklist

• I have read the Contribution Guidelines.
• My code is tested to the best of my abilities.
• My code passes all lints (PHPCS, PHPStan, ESLint, etc.).
• My code has detailed inline documentation.
• I have added unit tests to verify the code works as intended.
• I have updated the project documentation accordingly.