chore: Add entire team as code owners for the changelog and Cargo.lock (#2655)

Because virtually every PR may change these, and anyone in the team
should be able to vet changes to these files.

Author: netrome

.github/CODEOWNERS

@@ -34,3 +34,7 @@ docs/ @xgreenx @Dentosal @MitchTurner @netrome
 
 # Code owners for the fraud proofs
 crates/fraud_proofs @xgreenx @netrome @acerone85 @rymnc
+
+# Code owners for common files
+CHANGELOG.md @xgreenx @Dentosal @MitchTurner @netrome @acerone85 @rafal-ch @rymnc @AurelienFT
+Cargo.lock @xgreenx @Dentosal @MitchTurner @netrome @acerone85 @rafal-ch @rymnc @AurelienFT