Restore unjustly deleted changelog

Author: sergv

changelog.d/pr-10828.md

@@ -0,0 +1,15 @@
+---
+synopsis: "Isolate Cabal from the GHC_ENVIRONMENT variable"
+packages: [Cabal]
+prs: 10828 10990
+
+issues: 10759
+---
+
+For GHC 8.4.4 and later, Cabal now passes the `-package-env=-` flag to GHC.
+This prevents the `GHC_ENVIRONMENT` variable or any package environment files
+from affecting Cabal builds.
+
+This change eliminates unexpected build behavior that could occur when users
+had GHC environment files configured in their system that Cabal wasn't aware
+of.