Remove archives of Run-2 campaigns from stripping21-patches

Since S21rXp1 were produced during 2016, stripping21-patches contains archives for 2015-early 2016 campaigns, namely Stripping22, 23, 23r1, 24, 25, 26, which can't be ran with DV v39r* series. This causes compilation problems in the nightlies and will cause problems with the tests as well. I decided to remove these archives from stripping21-patches since they are present already in other Run 2 branches.

Regarding DaVinci: DaVinciTests does not have any test, they will be added for this S21rXp2. On the other hand, Phys/StrippingCache is also being cleaned up, see DaVinci!294 (merged).