build the pipelines image from Dockerfile (!205)

This adds a Dockerfile to build an image for the pipelines, once and for all, until we decide to bump the Rust toolchain.

## changelog
- add `.gitlab-ci.dockerfile` which
  - uses `rust:latest` as a base (it appears using `alpine:latest` is both bigger and slower 🤷)
  - installs basic system dependencies
  - uses `rust-toolchain.toml` to install the toolchain of the project
  - installs `cargo-script`
- use [`gitlab-registry.isae-supaero.fr/dragoon/komodo:bcb0e6b5`](https://gitlab.isae-supaero.fr/dragoon/komodo/container_registry/42) in the GitLab pipelines and [`ghcr.io/dragoon-rs/dragoon/komodo:bcb0e6b5`](https://github.com/orgs/dragoon-rs/packages/container/dragoon%2Fkomodo/388672772?tag=bcb0e6b5f73420762f6208700a43291e0066c2c3) in the GitHub pipelines and remove the "manual" dependency installation
- add `./make.rs container`, `./make.rs container --login` and `./make.rs container --push`
  - uses `nob.rs@7ea6be8` to capture output of commands with `+` syntax
  - get the current Git SHA as the tag of the image
- instructions have been added to the `README.md` for later reference

## mirror
| id                                                                             | head_sha                                                                                                                           | status    | conclusion | run_started_at        |
| ------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------- | --------- | ---------- | --------------------- |
| [`14262324842`](https://github.com/dragoon-rs/komodo/actions/runs/14262324842) | [`c93d9c87`](https://github.com/dragoon-rs/komodo/commit/c93d9c87928964aa20f347c1302757a06d2da628) | completed | success    | `2025-04-04T11:28:30` |
| [`14262372440`](https://github.com/dragoon-rs/komodo/actions/runs/14262372440) | [`f905e576`](https://github.com/dragoon-rs/komodo/commit/f905e57633f5e3dc7b1c38faa463daf54fb674bb) | completed | cancelled  | `2025-04-04T11:31:12` |
| [`14262477396`](https://github.com/dragoon-rs/komodo/actions/runs/14262477396) | [`21b26efd`](https://github.com/dragoon-rs/komodo/commit/21b26efd988b2d8d7159d24cae37341135cfb1b9) | completed | success    | `2025-04-04T11:36:59` |
| [`14263257396`](https://github.com/dragoon-rs/komodo/actions/runs/14263257396) | [`5bdca8cd`](https://github.com/dragoon-rs/komodo/commit/5bdca8cdb96e6ac2c25035513721485bcb08645d) | completed | success    | `2025-04-04T12:22:10` |
| [`14263314072`](https://github.com/dragoon-rs/komodo/actions/runs/14263314072) | [`bcb0e6b5`](https://github.com/dragoon-rs/komodo/commit/bcb0e6b5f73420762f6208700a43291e0066c2c3) | completed | success    | `2025-04-04T12:25:27` |
| [`14263368772`](https://github.com/dragoon-rs/komodo/actions/runs/14263368772) | [`ddd4a2a9`](https://github.com/dragoon-rs/komodo/commit/ddd4a2a9c1c28f4502814065de6aeca00b8b7a2f) | completed | success    | `2025-04-04T12:28:30` |
| [`14263575177`](https://github.com/dragoon-rs/komodo/actions/runs/14263575177) | [`f9400e61`](https://github.com/dragoon-rs/komodo/commit/f9400e619a066294714024174dacd4a0501a369c) | completed | success    | `2025-04-04T12:40:44` |



## speed
the performance appears to be around
- ~ 1min 35sec on GitLab (see
    [8331](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8331),
    [8332](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8332),
    [8333](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8333),
    [8334](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8334),
    [8335](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8335),
    [8336](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8336),
    [8337](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8337),
    [8338](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8338),
    [8339](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8339),
    [8340](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8340),
    [8341](https://gitlab.isae-supaero.fr/dragoon/komodo/-/pipelines/8341),
    all after b82e8950)
- ~ 4min on GitHub (see
    [14263257396](https://github.com/dragoon-rs/komodo/actions/runs/14263257396),
    [14263314072](https://github.com/dragoon-rs/komodo/actions/runs/14263314072),
    [14263368772](https://github.com/dragoon-rs/komodo/actions/runs/14263368772),
    [14263575177](https://github.com/dragoon-rs/komodo/actions/runs/14263575177),
    all after [5bdca8cd](https://github.com/dragoon-rs/komodo/commit/5bdca8cdb96e6ac2c25035513721485bcb08645d))