kbuild: rust: use -Zdebuginfo-compression

Rust 1.74.0 introduced (unstable) support for the
`-Zdebuginfo-compression` flag, thus use it.

Link: rust-lang/rust#120953
Link: rust-lang/rust#115358
Link: https://lore.kernel.org/r/20240217002622.57322-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

scripts/Makefile.debug

@@ -35,10 +35,12 @@ endif
 
 ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZLIB
 DEBUG_CFLAGS	+= -gz=zlib
+DEBUG_RUSTFLAGS	+= -Zdebuginfo-compression=zlib
 KBUILD_AFLAGS	+= -gz=zlib
 KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
 else ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZSTD
 DEBUG_CFLAGS	+= -gz=zstd
+DEBUG_RUSTFLAGS	+= -Zdebuginfo-compression=zstd
 KBUILD_AFLAGS	+= -gz=zstd
 KBUILD_LDFLAGS	+= --compress-debug-sections=zstd
 endif