Finalize changelog for v1.40.1 (#4885)

Author: kinke

CHANGELOG.md

@@ -1,5 +1,13 @@
 # LDC master
 
+#### Big news
+
+#### Platform support
+
+#### Bug fixes
+
+# LDC 1.40.1 (2025-03-20)
+
 #### Big news
 - Frontend and druntime bumped to version [2.110.0](https://dlang.org/changelog/2.110.0.html) final. (#4854, #4868)
 - LLVM for prebuilt packages bumped to v19.1.7. (#4822)