Linux

fix race condition when cancelling requests after becoming a seed #3266

Job	Run time
build (asio-debugging=on picker-debugging=on)	29m 12s
build (extensions=off logging=off streaming=off super-seeding=off share-mode=off predictive-piece...	22m 12s
build (crypto=gcrypt)	25m 21s
build (mmap-disk-io=off)	28m 16s
check headers	3m 53s
clang-tidy	9m 47s
build dist (ubuntu-20.04)	17m 46s
build dist (ubuntu-22.04)	15m 46s
Fuzzers	9m 11s
pre-commit	40s
Simulations	13m 14s
Tests (address-sanitizer=norecover undefined-sanitizer=norecover crypto=openssl)	16m 27s
Tests (toolset=clang logging=off address-sanitizer=norecover undefined-sanitizer=norecover)	11m 36s
Tests (thread-sanitizer=norecover crypto=openssl release debug-symbols=on cxxflags=-Wno-tsan)	18m 46s
Tests (crypto=gnutls)	12m 21s
Tests (deprecated-functions=off)	11m 15s
	4h 5m 43s

Provide feedback