PR
- https://github.com/zrepl/zrepl/pull/913
didn't update the `release-docker` flow to use `uv`, thereby breaking
it.
## Changes
- Create `.uv-version` file to centralize UV version between Dockerfile
and CircleCI
- Update build container to use `uv`
While at it, make life with the build container better:
- Create `zrepl_build` user in the build container as same UID/GID as
the caller of `make release-docker`
- Allow Ctrl-C to cancel `make release-docker` in interactive shells
Christian Schwarz