Various webgl fixes for framebuffer attachment test
These changes resolve all panics on macOS when running framebuffer-object-attachment.html in headless and headful testing.
---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] There are tests for these changes OR
- [x] Fixes#13710. Fixes#20570.
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/21461)
<!-- Reviewable:end -->
The expectation change is due to the shader now using its DOM-side compile status.
It is actually a bug for the shader to think it actually compiled successfully,
but at least it does so consistently now.
Respect the source rectangle when drawing a canvas to another canvas.
This allows us to run the three.js examples without panicking, since they use self-drawing canvases to scroll the FPS graph.
---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] There are tests for these changes
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/20923)
<!-- Reviewable:end -->
Don't forward GL parameter gets for constant limits.
This avoids IPC traffic for unchanging constants that are determined when the GL context is created. These changes require https://github.com/emilio/rust-offscreen-rendering-context/pull/123.
---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#20876.
- [x] There are tests for these changes
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/20884)
<!-- Reviewable:end -->
Implement WebGL GetRenderbufferParameter
This needed a bump of gleam to version 0.4.33 for this https://github.com/servo/gleam/pull/162
<!-- Please describe your changes on the following line: -->
I think my changes in test expectations are pretty naive and I have to wait for the PR to run on CI to see what the actual impact is. I'd like some guidance on this, too.
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach build-geckolib` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#20514 (github issue number if applicable).
<!-- Either: -->
- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____
<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->
<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/20631)
<!-- Reviewable:end -->
