Revert "presets: Update swift macos/linux preset"

This reverts commit fffc437.

Author: bkhouri

utils/build-presets.ini

@@ -609,10 +609,8 @@ mixin-preset=
     buildbot_incremental_base
     lldb-smoketest,tools=RA
     mixin_buildbot_install_components_with_clang
-    mixin_swiftpm_base
 build-subdir=buildbot_incremental
 
-skip-test-swift=false
 # We build release+asserts.
 release
 assertions
@@ -1079,7 +1077,6 @@ mixin-preset=
 mixin-preset=
     mixin_lightweight_assertions,no-stdlib-asserts
     mixin_linux_installation
-    mixin_swiftpm_base
 build-subdir=buildbot_linux
 lldb
 release
@@ -1097,7 +1094,6 @@ install-swiftformat
 reconfigure
 test-optimized
 skip-test-swiftdocc
-skip-test-swift=false
 
 # gcc version on amazon linux 2 is too old to configure and build tablegen.
 # Use the clang that we install in the path for macros