Fix vip-real-time-collaboration integration failed constant checks

[maxschmeling]

Description

Fixes an issue from #6731 where the vip-real-time-collaboration integration constants were moved to class constants but the defined() checks weren't removed.

Changelog Description

Fixed

• The vip-real-time-collaboration integration loading issues.

Pre-review checklist

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• This change works and has been tested locally or in Codespaces (or has an appropriate fallback).
• This change works and has been tested on a sandbox.
• This change has relevant unit tests (if applicable).
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• This change has relevant documentation additions / updates (if applicable).
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[Copilot]

Pull request overview

This PR fixes the Real-Time Collaboration (RTC) integration so it no longer relies on undefined global version constants and instead consistently uses internal class constants, ensuring the integration can resolve the correct plugin and Gutenberg paths.

Changes:

• Standardizes RTC plugin loading to use the RealTimeCollaborationIntegration::VIP_RTC_PLUGIN_VERSION class constant when building the plugin path.
• Standardizes RTC Gutenberg loading to use the RealTimeCollaborationIntegration::VIP_RTC_GUTENBERG_VERSION class constant, simplifying the logic for choosing the unversioned vs. versioned Gutenberg folders.
• Updates the default Gutenberg version string from 22.4.1-f48ad9c to 0.2, aligning it with the RTC plugin version constant.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 35.22%. Comparing base (05d1923) to head (3bd5f2b).
⚠️ Report is 16 commits behind head on develop.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #6740      +/-   ##
=============================================
+ Coverage      35.19%   35.22%   +0.02%     
+ Complexity      5085     5081       -4     
=============================================
  Files            295      295              
  Lines          20844    20840       -4     
=============================================
+ Hits            7337     7341       +4     
+ Misses         13507    13499       -8     

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[sonarqubecloud]

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 SonarQube Cloud