Upgrade to Rails 7.2 and Ruby 3.3

[david-yz-liu]

Proposed Changes

(Describe your changes here. Also describe the motivation for your changes: what problem do they solve, or how do they improve the application or codebase? If this pull request fixes an open issue, use a keyword to link this pull request to the issue.)

This pull request updates MarkUs to Rails 7.2. Because Rails 7.2 requires Ruby 3.1, I also upgraded the Docker image to use Ruby 3.3. Note that this required installing Ruby from source, since only Ruby 3.0 is available in the Ubuntu package repository.

Major changes:

1. Dockerfile modified to install Ruby 3.3 from source (using ruby-install).
2. Dockerfile modified to remove the deprecated bundler --without option.
3. Dockerfile modified to use the jemalloc memory allocator with Ruby.
4. Added csv to Gemfile, as this is scheduled to be removed in Ruby 3.4.
5. Switch Gemfile to install newer versions of shoulda-context and shoulda-matchers (the wrapper gem shoulda is infrequently updated) to support Rails 7.2.
6. Adopt a few more Rails defaults (bin/brakeman, config/initializers/filter_parameter_logging.rb, config/initializers/permissions_policy.rb).

Screenshots of your changes (if applicable)

Associated documentation repository pull request (if applicable)

Type of Change

(Write an X or a brief description next to the type or types that best describe your changes.)

Type	Applies?
🚨 Breaking change (fix or feature that would cause existing functionality to change)
✨ New feature (non-breaking change that adds functionality)
🐛 Bug fix (non-breaking change that fixes an issue)
🎨 User interface change (change to user interface; provide screenshots)
♻️ Refactoring (internal change to codebase, without changing functionality)
🚦 Test update (change that only adds or modifies tests)
📦 Dependency update (change that updates a dependency)	X
🔧 Internal (change that only affects developers or continuous integration)	X

Checklist

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Before opening your pull request:

• I have performed a self-review of my changes.
  • Check that all changed files included in this pull request are intentional changes.
  • Check that all changes are relevant to the purpose of this pull request, as described above.
• I have added tests for my changes, if applicable.
  • This is required for all bug fixes and new features.
• I have updated the project documentation, if applicable.
  • This is required for new features.
• If this is my first contribution, I have added myself to the list of contributors.

After opening your pull request:

• I have updated the project Changelog (this is required for all changes).
• I have verified that the pre-commit.ci checks have passed.
• I have verified that the CI tests have passed.
• I have reviewed the test coverage changes reported by Coveralls.
• I have requested a review from a project maintainer.

Questions and Comments

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