Disable catalyst builds again

While clang and the build-system can now handle generating
Catalysit-supporting executables, the OSS swift-frontend is missing
something.

This is failing in:
  SILGen/availability_query_maccatalyst_zippered_canonical_versions.swift

The compiler is only emitting the availability check-info for the macOS
target, not the iOS target.

e.g. for the following snippet

```
if #available(OSX 10.16, iOS 51.1.2, *) {
}
```

We end up emitting the literal checks for

integer_literal $Builtin.Word, 10
integer_literal $Builtin.Word, 16
integer_literal $Builtin.Word, 0

but we're missing

integer_literal $Builtin.Word, 51
integer_literal $Builtin.Word, 1
integer_literal $Builtin.Word, 2

This would be a most unfortunate miscompile.

Author: etcwilde

utils/build-presets.ini

@@ -1234,7 +1234,6 @@ mixin-preset=mixin_buildbot_install_components_with_clang
 ios
 tvos
 watchos
-maccatalyst
 
 lldb
 llbuild