Merge branch 'v2.9' into v2.10

Author: GiovanniBussi

CHANGES/v2.9.md

@@ -76,3 +76,5 @@ Changes from version 2.8 which are relevant for users:
 ## Version 2.9.5 (coming)
   - Fixed bug in derivatives of COSINUS switching function (see \issue{1317}.
   - Searching with bisection instead of linearly in the neigbourlist speeding up all CVs using NL.
+  - Added FMT keyword in \ref METAINFERENCE
+  - Several fixes in regression tests and in CI