Backport "timedate: handle gracefully if RTC lost time because of power loss" (v254)

[chombourger]

Apparently some RTC drivers return EINVAL in that case when we try to read it. Handle that reasonably gracefully.

Fixes: #31854
(cherry picked from commit 5c81de9)

[chombourger]

Not sure if this is the proper way to ask for a specific patch to be backported/integrated into a -stable release
One of our embedded device uses a 3rd party RTC driver that return EINVAL and this fix is exactly what we would need to handle this case gracefully

[yuwata]

Sorry for late review. LGTM. But let's first backport this to v255.
#470

[packit-as-a-service]

We were not able to find or create Copr project packit/systemd-systemd-stable-445 specified in the config with the following error:

Cannot create a new Copr project (owner=packit project=systemd-systemd-stable-445 chroots=[]): chroots: '[]' is not a valid choice for this field..

---

Unless the HTTP status code above is >= 500, please check your configuration for:

1. typos in owner and project name (groups need to be prefixed with @)
2. whether the project name doesn't contain not allowed characters (only letters, digits, underscores, dashes and dots must be used)
3. whether the project itself exists (Packit creates projects only in its own namespace)
4. whether Packit is allowed to build in your Copr project
5. whether your Copr project/group is not private

[yuwata]

#470 is merged. Rebased.

[bluca]

I'll handle this in the other PR