minimal-bootstrap: drop patchelf compiler reference

Static patchelf does not need build-compiler paths in debug or source metadata. Add deterministic compiler flags and disallow references to the bootstrap compiler.

Size impact against upstream/staging:

- patchelf-static closure: 167.634 MiB -> 1.237 MiB (-166.397 MiB)

Assisted-by: codex with gpt-5.5-high

pkgs/os-specific/linux/minimal-bootstrap/patchelf/static.nix

@@ -43,6 +43,8 @@ bash.runCommand "${pname}-${version}"
       gzip
     ];
 
+    disallowedReferences = [ gcc ];
+
     passthru.tests.get-version =
       result:
       bash.runCommand "${pname}-get-version-${version}" { } ''
@@ -70,7 +72,7 @@ bash.runCommand "${pname}-${version}"
       --host=${hostPlatform.config} \
       --disable-dependency-tracking \
       CC=musl-gcc \
-      CXXFLAGS=-static
+      CXXFLAGS="-static -g0 -O2 -DNDEBUG -ffile-prefix-map=${gcc}=. -fmacro-prefix-map=${gcc}=."
 
     # Build
     make -j $NIX_BUILD_CORES