[compat] Fix or skip context dependent res cases (#3858)

These tests should pass in Tint following the implementation of context
dependent resolution of the interpolate attribute, but there are a
couple cases that need fixing or skipping in compat mode.

src/webgpu/shader/validation/decl/context_dependent_resolution.spec.ts

@@ -314,10 +314,20 @@ g.test('interpolation_type_names')
       .beginSubcases()
       .combine('decl', ['override', 'const', 'var<private>'] as const)
   )
+  .beforeAllSubcases(t => {
+    t.skipIf(
+      t.isCompatibility && t.params.case === 'linear',
+      'compatibility mode does not support linear interpolation type'
+    );
+  })
   .fn(t => {
+    const attr =
+      t.isCompatibility && t.params.case === 'flat'
+        ? `@interpolate(flat, either)`
+        : `@interpolate(${t.params.case})`;
     const code = `
     ${t.params.decl} ${t.params.case} : u32 = 0;
-    @fragment fn main(@location(0) @interpolate(${t.params.case}) x : f32) { }
+    @fragment fn main(@location(0) ${attr} x : f32) { }
     fn use_var() -> u32 {
       return ${t.params.case};
     }