Change beta to pre in version string

What does this MR do?

Change beta to pre in version string

As discussed in #31098 (closed), the ~beta part in the version string concerns users. Especially because it's what we print for jobs executed on GitLab.com Hosted Runenrs.

Whatever we merge to main (which now will be released as vX.Y.Z~pre.N.gSHA) we consider ready for the next stable release and stable is just created on whatever is on main at the decision day.

We're also deploying these versions to our Hosted Runners in a form of a rolling update, for which pre also makes more sense.

Why was this MR needed?

What's the best way to test this MR?

What are the relevant issue numbers?

Closes Change runner version naming from `beta` to `pr... (#31098 - closed) • Tomasz Maczukin • 16.11