Test that tokenization does not tokenize >= into a single token

[stefnotch]

I found a bug in the current parser :D
The tokenization turns >= into a single token, but the template parsing expects to be able to yoink the > from the >=

[mighdoll]

Perhaps the tokens() combinator.. to give the template parser separate tokenization

[mighdoll]

I think this is fixed in the current grammar (which uses a separate tokenizer to recognize brackets)..

[stefnotch]

We should still have a unit test like that. I'll make sure that this PR gets updated, and that it also includes the test case from
gfx-rs/wgpu#6898

(Turns out that even wgpu sometimes struggles with those templates)

[stefnotch]

We have test("var foo: vec2<f32 >= vec2( 0.5, -0.5);", ctx => { in ParseWESL.test.ts