Fix MCMCChains >= 7.2.1 in CI

Author: penelopeysm

test/Project.toml

@@ -43,7 +43,7 @@ EnzymeCore = "0.6 - 0.8"
 ForwardDiff = "0.10.12, 1"
 JET = "0.9, 0.10"
 LogDensityProblems = "2"
-MCMCChains = "6.0.4, 7"
+MCMCChains = "7.2.1"
 MacroTools = "0.5.6"
 OrderedCollections = "1"
 ReverseDiff = "1"