t: add greplint.pl and convert grep to test_grep #28327

Job	Run time
config	10s
fuzz smoke test	2m 7s
win build	10s
rust-analysis	10s
static-analysis	10s
sparse	10s
win+VS build	-1s
osx-reftable (macos-14)	10s
documentation	10s
osx-meson (macos-14)	10s
osx-gcc (macos-14)	10s
linux-reftable (ubuntu:rolling)	10s
osx-clang (macos-14)	10s
linux-sha256 (ubuntu:rolling)	10s
linux-musl-meson (alpine:latest)	10s
linux-leaks (ubuntu:rolling)	10s
win+Meson build	10s
linux32 (i386/ubuntu:focal)	10s
linux-meson (ubuntu:rolling)	10s
linux-breaking-changes (ubuntu:rolling)	10s
linux-asan-ubsan (ubuntu:rolling)	10s
fedora-breaking-changes-meson (fedora:latest)	10s
linux-reftable-leaks (ubuntu:rolling)	10s
almalinux-8 (almalinux:8)	10s
linux-TEST-vars (ubuntu:20.04)	10s
debian-11 (debian:11)	10s
win+VS test	0s
win test	0s
win+Meson test	0s
	6m 6s

Provide feedback