Release checklist for 2.0.18

[jrfnl]

PRs to cherrypick into the next 2.0.x release (if there will be one):

• Requests::VERSION: move to top of the class #1018
• PHPUnit: add clover code coverage config to config file #1021
• GH Actions/website: update PHP version used by phpDocumentor #1022
• GH Actions: Bump the action-runners group with 2 updates #1023
• GH Actions: Bump actions/upload-artifact from 5.0.0 to 6.0.0 #1024
• GH Actions: Bump actions/cache from 4.3.0 to 5.0.1 #1025
• GH Actions: Bump peter-evans/create-pull-request from 7.0.11 to 8.0.0 #1026
• GH Actions: Bump actions/download-artifact from 6.0.0 to 7.0.0 #1027
• GH Actions: Bump ruby/setup-ruby from 1.270.0 to 1.275.0 in the action-runners group #1028
• GH Actions: Bump ruby/setup-ruby from 1.275.0 to 1.276.0 in the action-runners group #1030
• GH Actions: Bump ruby/setup-ruby from 1.276.0 to 1.278.0 in the action-runners group #1031
• GH Actions: Bump ruby/setup-ruby from 1.278.0 to 1.281.0 in the action-runners group #1032
• GH Actions: Bump the action-runners group with 2 updates #1033
• GH Actions: Bump the action-runners group across 1 directory with 5 updates #1035
• GH Actions: Bump the action-runners group with 2 updates #1036
• GH Actions: Bump actions/upload-artifact from 6.0.0 to 7.0.0 #1037
• GH Actions: Bump actions/download-artifact from 7.0.0 to 8.0.0 #1038
• 🔏 Update certificate bundle #1039
• GH Actions: Bump the action-runners group with 5 updates #1040
• GH Actions: Bump ramsey/composer-install from 3.2.0 to 4.0.0 #1041
• GH Actions: Bump ruby/setup-ruby from 1.295.0 to 1.299.0 in the action-runners group #1044
• GH Actions: Bump codecov/codecov-action from 5.5.3 to 6.0.0 #1045