Update GitHub Actions workflows

[iby]

trafficstars

Update GitHub Actions workflows to use latest actions and update testing (Quick and Nimble) dependencies—this improves compatibility with the current Xcode 15 and CI environment:

• Use compatible Quick and Nimble versions.
• Tweak auto-releasing test code that uses windows – it stopped working with beforeEach/afterEach calls as something keeps retaining released references.
• UIRefreshControl needs to be attached to a window to work correctly from iOS 17.