Update RDF module to ~3.0 to support Drupal 11

Problem/Motivation

#3336112: Remove RDF deprecated and obsolete extension from the install process of Varbase SEO
#3336115: Remove leftover configs for RDF

As part of #3457641: Update Drupal Core to ~10.3.0 and ~11.0.0 with support for recipes in Varbase SEO version requirements

• Switched to a Default Varbase SEO recipe and drop the use of the Module Installer Factory class in favour of Drupal Recipes
• Changed drupal/rdf to ~2 || ~3 in the composer.json file ( only for the 9.1.x branch and not install the RDF module
• Removed RDF leftover configs from booth 9.1.x and 10.0.x branches

Proposed resolution

• Change drupal/rdf to ~3 in the composer.josn file for the 9.1.x branch.

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ✅ Code review from 1 Varbase core team member
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Update Release Notes and Update Helper on new feature change/addition
• ✅ Release varbase-9.1.9, varbase_seo-9.1.6

Varbase update type

• ✅ No Update
• ➖ Optional Update
• ➖ Forced Update
• ➖ Forced Update if Unchanged

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Issue #3501127: Updated RDF module to ~3.0 to support Drupal 11