t: add greplint.pl and convert grep to test_grep #28472

Job	Run time
config	9s
fuzz smoke test	1m 31s
sparse	7m 14s
static-analysis	7m 14s
win build	7m 14s
win+Meson build	7m 14s
documentation	7m 14s
rust-analysis	7m 14s
osx-meson (macos-14)	7m 14s
osx-clang (macos-14)	7m 14s
osx-gcc (macos-14)	7m 14s
linux-asan-ubsan (ubuntu:rolling)	7m 14s
linux-sha256 (ubuntu:rolling)	7m 14s
osx-reftable (macos-14)	7m 14s
linux-reftable (ubuntu:rolling)	7m 14s
linux-meson (ubuntu:rolling)	7m 14s
linux-leaks (ubuntu:rolling)	7m 14s
linux-reftable-leaks (ubuntu:rolling)	7m 14s
linux-musl-meson (alpine:latest)	7m 14s
almalinux-8 (almalinux:8)	7m 14s
debian-11 (debian:11)	7m 14s
fedora-breaking-changes-meson (fedora:latest)	7m 14s
linux32 (i386/ubuntu:focal)	7m 14s
linux-breaking-changes (ubuntu:rolling)	7m 14s
linux-TEST-vars (ubuntu:20.04)	7m 14s
win+VS build	0s
win+VS test	0s
win test	-1s
win+Meson test	-1s
	2h 48m 0s

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