Auto merge of #18973 - MortimerGoro:offscreen_v12, r=jdm

Update offscreen_gl_context to v0.12

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Update offscreen_gl_context to v0.12. Includes:

- Support for OpenGL version selection. It's required for WebGL 2.
- Support for iOS EAGLContext. WebGL should work out of the box once Servo is fully built on iOS.

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- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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components/script/Cargo.toml

@@ -64,7 +64,7 @@ msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
 nonzero = {path = "../nonzero"}
 num-traits = "0.1.32"
-offscreen_gl_context = { version = "0.11", features = ["serde"] }
+offscreen_gl_context = { version = "0.12", features = ["serde"] }
 open = "1.1.1"
 parking_lot = "0.4"
 phf = "0.7.18"