Update dreamfactory/df-core requirement from ~0.24 to ~0.25

Updates the requirements on [dreamfactory/df-core](https://github.com/dreamfactorysoftware/df-core) to permit the latest version.
- [Release notes](https://github.com/dreamfactorysoftware/df-core/releases)
- [Changelog](https://github.com/dreamfactorysoftware/df-core/blob/master/CHANGELOG.md)
- [Commits](dreamfactorysoftware/df-core@0.24.0...0.25.0)

---
updated-dependencies:
- dependency-name: dreamfactory/df-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -29,7 +29,7 @@
   "minimum-stability": "dev",
   "prefer-stable": true,
   "require":     {
-    "dreamfactory/df-core":   "~0.24",
+    "dreamfactory/df-core":   "~0.25",
     "dreamfactory/df-system": "~0.5"
   },
   "autoload":    {