Auto merge of #25246 - asajeffrey:gstplugin-framerates, r=Manishearth

Block the gstreamer plugin waiting for the next frame

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Get the GStreamer plugin to produce frames at the requested rate rather than relying on downstream elements to perform throttling.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #24833
- [x] These changes do not require tests because

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0 files changed, 0 insertions, 0 deletions