*: migrate to CC toolchains and Bazel 5.4.0

Change-Id: Iff3c0ddda4413dd0c5fa657a5b7813223e98611e
Reviewed-on: https://review.monogon.dev/c/monogon/+/1079
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/build/toolchain/llvm-efi/transition.bzl b/build/toolchain/llvm-efi/transition.bzl
index e2f7a8f..1edb86b 100644
--- a/build/toolchain/llvm-efi/transition.bzl
+++ b/build/toolchain/llvm-efi/transition.bzl
@@ -3,13 +3,13 @@
     Transition that enables building for an EFI environment. Currently only supports C code.
     """
     return {
-        "//command_line_option:crosstool_top": "//build/toolchain/llvm-efi:efi_cc_suite",
+        "//command_line_option:platforms": "//build/platforms:efi_amd64"
     }
 
 build_efi_transition = transition(
     implementation = _build_efi_transition_impl,
     inputs = [],
     outputs = [
-        "//command_line_option:crosstool_top",
+        "//command_line_option:platforms",
     ],
 )