Auto merge of #117364 - BlackHoleFox:farewell-bitcode-no-remorse, r=davidtwco

Remove legacy bitcode defaults from all Apple specs

Xcode 14 [deprecated bitcode with warnings](https://developer.apple.com/documentation/xcode-release-notes/xcode-14-release-notes#Deprecations) and now [Xcode 15 has dropped it completely](https://developer.apple.com/documentation/xcode-release-notes/xcode-15-release-notes#Deprecations). `rustc` should follow what the platform tooling is doing as well since it just increases binary sizes for no gain at this point.

`cc` made a [similar change last month](rust-lang/cc-rs#812).

Two things show this should have minimal impact:
- Apple has stopped accepting apps built with versions of Xcode (<14) that generate bitcode
- The app store has been stripping bitcode off IPA releases for over 2 years now.

I didn't nuke all the bitcode changes added in rust-lang/rust#71970 since maybe another target in the future could need mandatory bitcode embedding.

Staticlibs built for iOS still link correctly with XCode 15 against a test app when using a compiler built from this branch.

cc `@thomcc` `@keith`

Author: bors