meson: bump fix version

So I can tag this commit for a point release.
14 jobs for v3.120.1 in 6 minutes and 15 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Compile
passed #609884
aarch64 docker
aarch64

00:00:11

passed #609880
amd64 docker
linux

00:00:12

passed #609885
catalina amd64
macos

00:00:09

passed #609886
amd64 docker
scan

00:00:27

passed #609881
amd64 docker
static

00:00:28

passed #609882
amd64 docker
win32

00:00:09

passed #609883
amd64 docker
win64

00:00:09

 
  Test
passed #609888
gpu
gpu

00:01:55

79.08%
passed #609887
amd64 docker
llvmpipe

00:00:28

 
  Sanitize
passed #609889
gpu
asan

00:02:39

canceled #609910
gpu
msan

canceled #609909
gpu
ubsan

00:00:04

failed #609890
gpu
msan

00:01:46

failed #609891
gpu
ubsan

00:01:47