This PR includes information that highlights the importance of
updating Xcode on MacOS. I ran into problems building serenity
on MacOS because I had Xcode installed but not updated in a while.
This triggered seemingly unrelated errors that were easily solved
by updating Xcode.
This should prevent a build issue caused by a potential
conflicting zstd installation on M1 Mac.
This was manifested in a linker error when building
the GNU toolchain:
```
Undefined symbols for architecture arm64:
[gcc/build] "_ZSTD_compress", referenced from:
```
As of qemu 6.0.0, it should already have the entitlement to access the
Hypervior.framework by default, so re-codesigning the binary is
no-longer necessary.
8a74ce618b