There is no branch called SNAPSHOT.
If you refer by SNAPSHOT the main development branch snapshot builds, the command to switch into that branch is git checkout main (or master)
If you want 23.05-SNAPSHOT, you already have the correct 23.05 branch...
But also note that for e8450/rt3200, before the flashing the main/master firmware update you will need to run the correct new version of Daniel's ubi installer.