Add rate limiting middleware example and introduce tests for examples #15199

Job	Run time
Generate llhttp sources	5s
Pre-Setup global build settings	3s
Linter	57s
Benchmark	6m 20s
Test (3.11, macos, false)	7m 14s
Test (3.10, windows, false)	5m 41s
Test (3.10, macos, false)	7m 24s
Test (3.10, Y, ubuntu, false)	5m 34s
Test (3.11, Y, ubuntu, false)	5m 14s
Test (3.11, ubuntu, false)	3m 48s
Test (3.11, windows, false)	5m 12s
Test (3.13, macos, false)	6m 38s
Test (3.12, Y, ubuntu, false)	5m 34s
Test (3.13, windows, false)	5m 32s
Test (pypy-3.11, Y, ubuntu, false)	9m 18s
Test (3.14, windows, false)	6m 21s
Test (3.14, Y, ubuntu, false)	5m 34s
Test (3.12, ubuntu, false)	4m 18s
Test (3.14, macos, false)	7m 34s
Test (ubuntu, 3.14t, false)	3m 31s
Test (3.14, ubuntu, false)	4m 38s
Test (3.10, ubuntu, false)	4m 2s
Test (3.12, macos, false)	7m 24s
Test (3.12, windows, false)	7m 2s
Test (3.13, ubuntu, false)	4m 12s
Test (3.13, Y, ubuntu, false)	5m 14s
check	4s
Build wheels on ${{ matrix.os }} ${{ matrix.qemu }} ${{ matrix.musl }}	0s
Pre-Deploy	0s
Tarball	0s
Deploy	0s
	2h 14m 28s

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