B2STauTau 3pi3pi lines (bugfix naming conflict)

Addressing conflict mentioned by @yitang at !1832 (comment 6938311).

The selection with the name Combine_Tau3pi_DDK existed in both StrippingB2XTauTau.py and StrippingB2STauTauInclusive.py. A commit in the B2TauNu MR fixed this, but this was overwritten by the B2STauTau MR which for some reason didn't have this fix.

Thanks to @yitang and @yusong for catching this.

changed milestone to %2023 Re-Strip Campaign -- Development and Testing

added RD label

requested review from @yitang, @yusong, and @mbirch

assigned to @avenkate

mentioned in merge request !1832 (merged)

added all-slots label

Thanks for fixing that!

enabled an automatic merge when the pipeline for dd13da58 succeeds

mentioned in commit 55a17b8d

merged