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.

src/codeql.ts

@@ -634,6 +634,7 @@ export async function getCodeQLForCmd(
         [
           "database",
           "init",
+          "--overwrite",
           "--db-cluster",
           config.dbLocation,
           `--source-root=${sourceRoot}`,