Add missing rustc binaries to rustc_lib filegroup

Adds `rust-objcopy` and `wasm-component-ld` to the rustc_lib filegroup
in repository_utils.bzl. These binaries are present in recent rustc
distributions (wasm-component-ld since 1.82.0, rust-objcopy since 1.84.0)
but were not declared in the filegroup.

On Windows, Bazel copies files into the sandbox rather than symlinking,
so only explicitly listed files are available. This caused wasm32-wasip2
builds to fail with "linker 'wasm-component-ld.exe' not found".

On Linux/macOS, the issue was masked by symlink-based sandboxing which
allowed access to unlisted files in the same directory.

Author: avrabe

rust/private/repository_utils.bzl

@@ -47,6 +47,8 @@ filegroup(
             "lib/rustlib/{target_triple}/codegen-backends/*{dylib_ext}",
             "lib/rustlib/{target_triple}/bin/gcc-ld/*",
             "lib/rustlib/{target_triple}/bin/rust-lld{binary_ext}",
+            "lib/rustlib/{target_triple}/bin/rust-objcopy{binary_ext}",
+            "lib/rustlib/{target_triple}/bin/wasm-component-ld{binary_ext}",
             "lib/rustlib/{target_triple}/lib/*{dylib_ext}*",
             "lib/rustlib/{target_triple}/lib/*.rmeta",
         ],