Avoid multiple slice calls in the WebSocket reader #7386

Job	Run time
Linter	1m 13s
Generate llhttp sources	8s
Benchmark	2m 2s
Test (3.9, ubuntu, false)	6m 9s
Test (3.9, macos, false)	4m 59s
Test (3.9, windows, false)	6m 38s
Test (3.9, Y, ubuntu, false)	7m 9s
Test (3.10, ubuntu, false)	6m 22s
Test (3.10, macos, false)	4m 44s
Test (3.10, windows, false)	8m 36s
Test (3.10, Y, ubuntu, false)	7m 27s
Test (3.11, ubuntu, false)	6m 24s
Test (3.11, macos, false)	4m 46s
Test (3.11, windows, false)	9m 3s
Test (3.11, Y, ubuntu, false)	7m 23s
Test (3.12, ubuntu, false)	6m 37s
Test (3.12, macos, false)	5m 25s
Test (3.12, windows, false)	7m 26s
Test (3.12, Y, ubuntu, false)	7m 43s
Test (3.13, ubuntu, false)	6m 51s
Test (3.13, macos, false)	5m 9s
Test (3.13, windows, false)	8m 11s
Test (3.13, Y, ubuntu, false)	8m 5s
Test (pypy-3.9, Y, ubuntu, false)	13m 36s
Test (ubuntu, 3.14, true, Y)	3m 2s
check	4s
Pre-Deploy	0s
Build wheels on ${{ matrix.os }} ${{ matrix.qemu }}	0s
Tarball	0s
Deploy	0s
	2h 35m 12s

Provide feedback