Skip compiling RustDecoderTest on WASM

Change-Id: I95dbe75073c6fc8eba88e0a039f26f6fea872b84
Bug: chromium:356875275
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/912577
Auto-Submit: Kaylee Lubick <kjlubick@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

modules/canvaskit/compile_gm.sh

@@ -180,6 +180,7 @@ GLOBIGNORE+="tests/CodecTest.cpp:"\
 "tests/FontationsFtCompTest.cpp:"\
 "tests/FCITest.cpp:"\
 "tests/JpegGainmapTest.cpp:"\
+"tests/SkPngRustDecoderTest.cpp:"\
 "tests/TypefaceMacTest.cpp:"
 
 # These tests do complex things with TestContexts, which is not easily supported for the WASM