RUBY-3652 Remove serverless testing

[jamis]

Remove all testing of serverless (per DRIVERS-3115).

[Copilot]

Pull Request Overview

Removes all serverless testing functionality from the MongoDB Ruby driver per DRIVERS-3115. This includes removing serverless-specific methods, test configurations, and CI/CD infrastructure.

• Removes the serverless? method and related serverless detection logic
• Updates test requirements to handle deprecated serverless specifications
• Removes serverless-related CI/CD tasks and environment variables

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
spec/support/spec_config.rb	Removes serverless detection method and adds deprecation wrapper
spec/runners/unified/test.rb	Removes serverless-specific error handling for killAllSessions
spec/runners/crud/requirement.rb	Adds deprecation support for serverless requirements in test specs
spec/runners/crud.rb	Updates test skipping logic for serverless requirements
.evergreen/run-tests-atlas-full.sh	Replaces SERVERLESS environment variable with KILL_ALL_SERVER_SESSIONS
.evergreen/config/common.yml.erb	Removes serverless task groups and related CI infrastructure
.evergreen/config.yml	Removes serverless task groups and related CI infrastructure

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[Copilot]

[nitpick] The condition @serverless && @serverless != :forbid could be simplified to @serverless && @serverless != :forbid or extracted to a more descriptive method like should_warn_about_serverless? for better readability.

Suggested change

	end
	if should_warn_about_serverless?
	warn "The `serverless` requirement is deprecated."
	end
	end
	def should_warn_about_serverless?
	@serverless && @serverless != :forbid
	end