ci: Skip building non-native tests on aarch64-linux.

Because we don't pass -fqemu and -fwasmtime on aarch64-linux, we're just
spending a bunch of time compiling all these module tests only to not even run
them. x86_64-linux already covers both compiling and running them.

ci/aarch64-linux-debug.sh

@@ -52,6 +52,7 @@ ninja install
 stage3-debug/bin/zig build test docs \
   --maxrss 44918199637 \
   -Dstatic-llvm \
+  -Dskip-non-native \
   -Dtarget=native-native-musl \
   --search-prefix "$PREFIX" \
   --zig-lib-dir "$PWD/../lib" \

ci/aarch64-linux-release.sh

@@ -52,6 +52,7 @@ ninja install
 stage3-release/bin/zig build test docs \
   --maxrss 44918199637 \
   -Dstatic-llvm \
+  -Dskip-non-native \
   -Dtarget=native-native-musl \
   --search-prefix "$PREFIX" \
   --zig-lib-dir "$PWD/../lib" \