bazel: drop --swiftcopt/--host_swiftcopt flag aliases (no longer used)

Author: Copilot

.bazelrc

@@ -12,15 +12,6 @@ common --override_module=semmle_code=%workspace%/misc/bazel/semmle_code_stub
 
 build --repo_env=CC=clang --repo_env=CXX=clang++
 
-# Register the `--swiftcopt` / `--host_swiftcopt` command-line shortcuts.
-#
-# rules_swift defines these as `--flag_alias` entries in its own `.bazelrc`,
-# which Bazel does *not* load for consumer modules. Without registering them
-# here, any use of `--swiftcopt=...` (including via `build:macos` below) fails
-# with "Unrecognized option: --swiftcopt".
-common --flag_alias=swiftcopt=@rules_swift//swift:copt
-common --flag_alias=host_swiftcopt=@rules_swift//swift:exec_copt
-
 # Point Bazel at `apple_support`'s xcode_config on macOS.
 #
 # `xcode_swift_toolchain` pulls in `@system_sdk//:{all_modules,implicit_modules}`,