fix(dependabot): rename label uv to uv.lock (#100)

Label 'uv' did not exist in the repo, causing Dependabot to block
itself from opening PRs. Rename to 'uv.lock' which is now created.

Author: woutervh

.github/dependabot.yml

@@ -26,7 +26,7 @@ updates:
       labels:
           - "dependencies"
           - "python"
-          - "uv"
+          - "uv.lock"
       open-pull-requests-limit: 9
       schedule:
           interval: "monthly"