fix: Removes nullable from DBUser password (#564)

Author: cveticm

src/tools/atlas/create/createDBUser.ts

@@ -14,8 +14,7 @@ export const CreateDBUserArgs = {
     // AtlasPassword123, which are easily guessable and exploitable. We're instructing
     // the model not to try and generate anything and instead leave the field unset.
     password: AtlasArgs.password()
-        .optional()
-        .nullable()
+        .nullish()
         .describe(
             "Password for the new user. IMPORTANT: If the user hasn't supplied an explicit password, leave it unset and under no circumstances try to generate a random one. A secure password will be generated by the MCP server if necessary."
         ),