CompatHelper: bump compat for AbstractPPL to 0.4 for package test, (keep existing compat) (#344)

Co-authored-by: CompatHelper Julia <compathelper_noreply@julialang.org>

Author: github-actions[bot]

test/Project.toml

@@ -21,7 +21,7 @@ Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [compat]
 AbstractMCMC = "2.1, 3.0"
-AbstractPPL = "0.3"
+AbstractPPL = "0.3, 0.4"
 Bijectors = "0.9.5"
 Distributions = "0.25"
 DistributionsAD = "0.6.3"