Revert "Update CHANGELOG.md for 12.0.7"

This reverts commit 49858350.

changelogs/unreleased/security-project-import-bypass.yml

+---
+title: Fix project import restricted visibility bypass via API
+merge_request:
+author:
+type: security

changelogs/unreleased/security-sarcila-fix-weak-session-management.yml

+---
+title: Fix weak session management by clearing password reset tokens after login (username/email)
+  are updated
+merge_request:
+author:
+type: security

changelogs/unreleased/security-ssrf-kubernetes-dns.yml

+---
+title: Fix SSRF via DNS rebinding in Kubernetes Integration
+merge_request:
+author:
+type: security