Removed CurlHandlerPool and simplified it #1903

Job	Run time
macos12	22m 46s
macos12	23m 9s
Linux (ubuntu:24.04)	14m 9s
Linux (ubuntu:24.04)	14m 9s
MemoryTest (glibc_debug)	11m 15s
MemoryTest (glibc_debug)	11m 15s
Linux (ubuntu:22.04)	13m 37s
Linux (ubuntu:22.04)	13m 37s
MemoryTest (sanitize_address)	12m 35s
MemoryTest (sanitize_address)	12m 35s
Linux (ubuntu:20.04)	10m 29s
Linux (ubuntu:20.04)	10m 29s
MemoryTest (sanitize_others)	11m 17s
MemoryTest (sanitize_others)	11m 17s
Linux (debian:bookworm)	13m 40s
Linux (debian:bookworm)	13m 40s
MemoryTest (sanitize_thread)	1m 44s
MemoryTest (sanitize_thread)	1m 44s
Linux (debian:bullseye)	10m 49s
Linux (debian:bullseye)	10m 49s
MemoryTest (valgrind)	24m 40s
MemoryTest (valgrind)	24m 40s
Linux (rockylinux:9)	15m 28s
Linux (rockylinux:9)	15m 28s
Linux (rockylinux:8)	15m 53s
Linux (rockylinux:8)	15m 53s
Linux (fedora:40)	14m 20s
Linux (fedora:40)	14m 20s
Linux (fedora:39)	13m 58s
Linux (fedora:39)	13m 58s
Linux (opensuse/leap:15)	13m 19s
Linux (opensuse/leap:15)	13m 19s
Linux (alpine:3.20)	20m 13s
Linux (alpine:3.20)	20m 13s
Linux (centos:centos7)	37m 59s
Linux (centos:centos7)	37m 59s
	9h 16m 45s

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