m4: Fix check for Python 3.6 version. #3267

Job	Run time
linux deb no dpdk	4m 53s
dpdk gcc (ubuntu-24.04)	6s
linux rpm fedora	3m 57s
osx clang --disable-ssl	1m 29s
linux gcc --disable-ssl	2m 21s
linux clang --disable-ssl	2m 12s
linux gcc c99	2m 24s
linux clang c99	2m 21s
linux gcc test	7m 46s
linux clang test asan	13m 24s
linux clang test ubsan	9m 30s
linux gcc test --enable-shared	10m 57s
linux clang test --enable-shared	10m 12s
linux gcc test dpdk	8m 14s
linux clang test dpdk	7m 58s
linux gcc test -ljemalloc	8m 16s
linux clang test -ljemalloc	8m 18s
linux gcc --enable-afxdp	2m 24s
linux clang --enable-afxdp	2m 14s
linux gcc dpdk --enable-shared	3m 37s
linux clang dpdk --enable-shared	3m 2s
linux gcc dpdk-shared	2m 32s
linux clang dpdk-shared	2m 24s
linux gcc dpdk-shared --enable-shared	4m 3s
linux clang dpdk-shared --enable-shared	3m 5s
linux gcc m32 --disable-ssl	2m 27s
	2h 10m 6s

Provide feedback