Fixup storage texture var restrictions in test (gpuweb#3774)

Test cases for read-only storage textures should not be skipped as they
are permitted in vertex shaders.

This is a followup from:
gpuweb#3772 (comment)

src/webgpu/api/validation/render_pipeline/resource_compatibility.spec.ts

@@ -51,7 +51,8 @@ g.test('resource_compatibility')
     t.skipIf(
       t.params.stage === 'vertex' &&
         ((wgslResource.buffer !== undefined && wgslResource.buffer.type === 'storage') ||
-          wgslResource.storageTexture !== undefined),
+          (wgslResource.storageTexture !== undefined &&
+            wgslResource.storageTexture.access !== 'read-only')),
       'Storage buffers and textures cannot be used in vertex shaders'
     );
     const emptyVS = `