Change Details

``` Remove FORCE_USE_SYSTEM_CLANG in favour of always using the system Clang and lld for macOS cross-compilation; rather than downloading precompiled blobs. ``` Backport of core#30201 and core#30231. Depends on D17265. Note the CI update will be done in another diff. It only affects the cross osx build on CI which is currently paused.

``` Remove FORCE_USE_SYSTEM_CLANG in favour of always using the system Clang and lld for macOS cross-compilation; rather than downloading precompiled blobs. ``` Backport of [[https://github.com/bitcoin/bitcoin/pull/30201 | core#30201]] and [[https://github.com/bitcoin/bitcoin/pull/30231 | core#30231]]. Depends on D17265. Note the CI update will be done in another diff. It only affects the cross osx build on CI which is currently paused.

``` Remove FORCE_USE_SYSTEM_CLANG in favour of always using the system Clang and lld for macOS cross-compilation; rather than downloading precompiled blobs. ``` Backport of core#30201 and core#30231[[https://github.com/bitcoin/bitcoin/pull/30201 | core#30201]] and [[https://github.com/bitcoin/bitcoin/pull/30231 | core#30231]]. Depends on D17265. Note the CI update will be done in another diff. It only affects the cross osx build on CI which is currently paused.