firefox-common.profile: Add DRM support when using psd

[glitsj16]

We already added profile-sync-daemon (psd) support in firefox.profile with:
noblacklist ${RUNUSER}/psd/firefox
whitelist ${RUNUSER}/psd/firefox
This PR fixes DRM usage when using psd by ignoring noexec ${RUNUSER}.

[kmk3]

The code LGTM.

---

[firefox-common.profile] Add DRM support when using psd

This [file] format seems to be rarely used compared to file: :

$ git show --pretty='%h %ai %s' -s
29ccbcc45 2022-11-28 04:24:46 -0300 ci: ignore profile-checks.yml on other workflows
$ git log --pretty='%h %ai %s' -E --grep='\[[^[]+\]' |
  grep -E '\[[^[]+\]' | grep -Fv '[skip ci]'
86c6cd4b3 2022-11-25 04:39:56 +0000 [email-common.profile] add localtime to private-etc
d8a5f385b 2022-10-29 12:16:32 +0000 [StepSecurity] ci: Harden GitHub Actions Signed-off-by: StepSecurity Bot <bot@stepsecurity.io>
7a5c2b205 2022-09-13 20:21:21 +0000 tests: use bash-style [[...]] instead of [...]
25f7c7e0b 2021-10-22 14:56:01 -0300 util.c: [ref] move group find/copy into new functions
cc0a113e9 2021-10-16 02:16:45 -0300 main.c: [ref] fix indentation and whitespace around group handling
ed1f0c088 2021-08-01 14:05:24 +0200 Add electron[0-9]{0,2} to all electron redirect …
0d2cabef4 2021-05-29 10:49:24 +0200 [minor] gunzip profile broken (#4317)
fdf32b2b4 2021-03-04 00:43:30 +0100 private-lib: mask /usr/local/lib[,64] directories, too
17b717edc 2020-04-07 23:58:22 +0000 fix typos in dbus-{system,user}.talk [usage.c]
27eb40b84 2020-01-16 14:57:11 +0100 fix wire-desktop [1]
e48bb1fab 2019-06-19 04:14:37 +0000 Fix typo in man firejail [--x11] (#2785)
da89f5707 2019-03-16 23:28:25 +0100 minor enhancement: added robustness for setres[gu]id function calls
190059f3d 2018-06-23 22:33:07 +0000 Add 7za redirect profile [7z]
ad34123ee 2018-06-23 22:31:45 +0000 Add 7zr redirect profile [7z]
5cba25a8a 2018-06-23 22:30:26 +0000 Add p7zip redirect profile [7z]
$ git log --pretty='%h %ai %s' -E --grep='\[[^[]+\]' |
  grep -E '\[[^[]+\]' | grep -Fv '[skip ci]' | wc -l
15
$ git log --oneline -E --grep='^[0-9a-zA-Z_./-]+: ' |
  grep -E ' [0-9a-zA-Z_./-]+: ' | wc -l
858

Suggestion: Change the commit message to:

firefox-common.profile: Add DRM support when using psd

[kmk3]

(By the way, the CI errors can probably be fixed by rebasing to master)