Use latest scout steam runtime

[FreeSlave]

I noticed the steam scout runtime sdk from 2021 is not available anymore. Valve probably deleted old archives. Try using latest-public-beta instead.

If you're interested here's the list of snapshots: https://repo.steampowered.com/steamrt-images-scout/snapshots/

[FreeSlave]

huh, that's weird. Github used the cached tar.gz this time.
But for some reason it didn't use the cache when building for 387c266

Anyway, the .tar.gz from 2021 is gone. And we need to update the link.

[a1batross]

You can manually purge caches in https://github.com/FWGS/hlsdk-portable/actions/caches.

Also, I've looked into scout steamrt recently. It actually provides newer compilers and newer binutils. So maybe we could use them to avoid that vgui.so linking issue. At least, binutils upgrade would be nice to have.

[FreeSlave]

huh, that's weird. Github used the cached tar.gz this time.

Nevermind. It did download the steam runtime first time before I force-pushed with another commit name.

I'm making it more configurable by letting to choose the snapshot.

[FreeSlave]

Btw, I'm not sure what's difference between latest-public-beta, latest-steam-client-general-availability and latest-steam-client-public-beta. They all have the same BUILD_ID.txt currently.
Maybe they may become different when Valve is preparing the new runtime.

Here it explains that latest-steam-client-general-availability should be used usually.

[FreeSlave]

I set it to latest-steam-client-general-availability and squashed the commits.
Please review again.

You may also delete redundant steam-runtime-latest-public-beta cache from actions.

[FreeSlave]

@nekonomicon merge?