Revert "presets: Update swift macos/linux preset"

This reverts commit c9f97e9.

Author: bkhouri

utils/build-presets.ini

@@ -609,7 +609,6 @@ mixin-preset=
     buildbot_incremental_base
     lldb-smoketest,tools=RA
     mixin_buildbot_install_components_with_clang
-    mixin_swiftpm_base
 build-subdir=buildbot_incremental
 
 # We build release+asserts.
@@ -1078,7 +1077,6 @@ mixin-preset=
 mixin-preset=
     mixin_lightweight_assertions,no-stdlib-asserts
     mixin_linux_installation
-    mixin_swiftpm_base
 build-subdir=buildbot_linux
 lldb
 release