Add the overwrite flag when init-ing databases

This ensures that if there is a database already in the filesystem, we
can gracefully handle creating a new one. This sometimes happens when
a user is on a self-hosted runner and neglects to clean state across
runs.

Author: aeisenberg

CHANGELOG.md

@@ -6,7 +6,7 @@ Note that the only difference between `v2` and `v3` of the CodeQL Action is the
 
 ## [UNRELEASED]
 
-No user facing changes.
+- Automatically overwrite an existing database if found on the filesystem. [#2229](https://github.com/github/codeql-action/pull/2229)
 
 ## 3.24.10 - 05 Apr 2024