wasm: disable division test

Seems that bit integers are not properly supported

Author: Snektron

test/behavior/math.zig

@@ -413,6 +413,7 @@ test "division" {
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_x86_64 and builtin.target.ofmt != .elf) return error.SkipZigTest;
 
     if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch.isMIPS()) {