[clang] [clang][NFC] Fix typos in clang release notes (PR #166064)

[Aaron Ballman via cfe-commits]

================
@@ -350,7 +350,7 @@ Improvements to Clang's diagnostics
   potential misaligned members get processed before they can get discarded.
   (#GH144729)
 
-- Clang now emits dignostic with correct message in case of assigning to const reference captured in lambda. (#GH105647)
+- Clang now emits diagnostic with correct message in case of assigning to const reference captured in lambda. (#GH105647)
----------------
AaronBallman wrote:

```suggestion
- Clang now emits a diagnostic with the correct message in case of assigning to 'const' reference captured in lambda. (#GH105647)
```

https://github.com/llvm/llvm-project/pull/166064