Removed CurlHandlerPool and simplified it #2194

Job	Run time
clang-tidy	3m 52s
clang-tidy	3m 52s
macos12	51m 59s
macos12	51m 59s
MemoryTest (glibc_debug)	11m 37s
MemoryTest (glibc_debug)	11m 37s
Linux (ubuntu:24.04)	11m 49s
Linux (ubuntu:24.04)	11m 49s
MemoryTest (sanitize_address)	13m 38s
MemoryTest (sanitize_address)	13m 38s
Linux (ubuntu:22.04)	12m 19s
Linux (ubuntu:22.04)	12m 19s
MemoryTest (sanitize_others)	12m 15s
MemoryTest (sanitize_others)	12m 15s
Linux (ubuntu:20.04)	10m 38s
Linux (ubuntu:20.04)	11m 11s
MemoryTest (sanitize_thread)	14m 20s
MemoryTest (sanitize_thread)	14m 20s
Linux (debian:bookworm)	11m 32s
Linux (debian:bookworm)	11m 32s
MemoryTest (thread_safety)	11m 48s
MemoryTest (thread_safety)	11m 48s
Linux (debian:bullseye)	10m 56s
Linux (debian:bullseye)	10m 56s
MemoryTest (valgrind)	24m 26s
MemoryTest (valgrind)	24m 26s
Linux (rockylinux:9)	13m 2s
Linux (rockylinux:9)	13m 2s
Linux (rockylinux:8)	12m 53s
Linux (rockylinux:8)	12m 53s
Linux (fedora:40)	11m 43s
Linux (fedora:40)	11m 43s
Linux (fedora:39)	12m 2s
Linux (fedora:39)	12m 2s
Linux (opensuse/leap:15)	12m 29s
Linux (opensuse/leap:15)	12m 29s
Linux (alpine:3.20)	11m 33s
Linux (alpine:3.20)	11m 33s
Linux (centos:centos7)	38m 32s
Linux (centos:centos7)	38m 32s
	10h 27m 19s

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