elements/components/patch.bst: use add .git suffix to the gnulib url

other elements have the suffix, and it would avoid cloning it twice
10 jobs for abderrahim/mesa-public in 122 minutes and 14 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Flatpak
passed #250904706
aarch64
app_aarch64

01:27:13

passed #250904707
armhf
app_arm

00:28:00

passed #250904704
cache_i686 x86_64
app_i686

00:57:42

passed #250904708
ppc64le allowed to fail
app_powerpc64le

00:34:54

passed #250904702
cache_x86_64 x86_64
app_x86_64

00:57:25

 
  Vm
manual #250904711
aarch64 allowed to fail manual
minimal_systemd_vm_aarch64
passed #250904712
armhf
minimal_systemd_vm_arm

00:09:12

passed #250904710
cache_i686 x86_64
minimal_systemd_vm_i686

00:34:59

manual #250904714
ppc64le allowed to fail manual
minimal_systemd_vm_powerpc64le
passed #250904709
cache_x86_64 x86_64
minimal_systemd_vm_x86_64

00:33:14