CompatHelper: bump compat for DiffEqCallbacks to 4 for package core, …

…(keep existing compat) (#1848)

This pull request changes the compat entry for the `DiffEqCallbacks`
package from `3.6` to `3.6, 4` for package core.
This keeps the compat entries for earlier versions.



Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass
before you merge this pull request.

Co-authored-by: CompatHelper Julia <[email protected]>

core/Project.toml

@@ -68,7 +68,7 @@ DataInterpolations = "6"
 DataStructures = "0.18"
 Dates = "<0.0.1, 1"
 DiffEqBase = "6.155"
-DiffEqCallbacks = "3.6"
+DiffEqCallbacks = "3.6, 4"
 EnumX = "1.0"
 FiniteDiff = "2.21"
 Graphs = "1.9"