Revert "'maxStorageBuffersInFragmentStage' and 'maxStorageBuffersInVertexStage' aren't (#4448)"

[greggman]

This reverts commit b500efd.

Compatibility mode is now part of the spec.
These limits are now required on all devices.

Issue: #4448, #4523

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Requirements for PR author:

• All missing test coverage is tracked with "TODO" or .unimplemented().
• New helpers are /** documented */ and new helper files are found in helper_index.txt.
• Test behaves as expected in a WebGPU implementation. (If not passing, explain above.)
• Test have be tested with compatibility mode validation enabled and behave as expected. (If not passing, explain above.)

Requirements for reviewer sign-off:

• Tests are properly located in the test tree.
• Test descriptions allow a reader to "read only the test plans and evaluate coverage completeness", and accurately reflect the test code.
• Tests provide complete coverage (including validation control cases). Missing coverage MUST be covered by TODOs.
• Helpers and types promote readability and maintainability.

When landing this PR, be sure to make any necessary issue status updates.

[kainino0x]

LGTM but how many tests does this impact? I.e. how many tests will be broken in browsers until they expose these new limits?

[greggman]

not that many? off the top of my head, webgpu:idl, has a couple of tests. requestDevice is in the PR so maybe that. Maybe requestAdapter. I think there might be 1 or 2 others.

I don't have an easy way to check. Running the entire CTS on a single browser takes ~6hrs (assuming it doesn't crash). I can't easily use chrome's CQ without making a change to remove the limits.

[kainino0x]

OK, that seems probably fine. We can revert again if needed.