Sanity bot does not recognize lts- named branches as valid pick targets

The sanity bot does not recognize lts branch targets where the branch is prefixed with tqtc/lts- or lts-. While this is typically not an issue in normal picking, as targets are bare minor branches (i.e. 6.2) and the cherry-pick bot takes care of the rest, if a fix must target an lts release branch directly for some reason, the pick target is not recognized. This is particularly likely to happen in repos with open-source lts branches such as yocto/* repos.

See Commit message · Gerrit Code Review (qt-project.org) for an example.

The bot should be aware of branches prefixed with lts- or tqtc/lts- and provide a -1 for these picks, as it is not the preferred picking method, but may need to be overridden from time to time.