Merge #332
332: fix ci image r=eguzki a=eguzki
### what
CI image was based on `quay.io/centos/centos:stream9` which reached EOL and cannot be used. When trying to build dev image from the CI image, the installation of the packages failed.
This PR depends on #325 because that PR updates the Gemfile, simplifying it. The new Gemfile removes some dependencies, one of them being `pg` which was used to access PostgreSQL. Since `pg` is no longer needed, postgreSQL is not needed in the CI image either. Thus, this PR removes postgreSQL from the CI image.
The new image is based on UBI 9 `registry.access.redhat.com/ubi9:9.1.0`.
Dev notes: there were some issues installing postgreSQL dependencies such as `bison`, `flex` and `readline-devel`. Since postgreSQL is no longer needed, the issues were gone.
Once merged, the new CI image must be pushed to `quay.io/3scale/apisonator-ci` to be used in the dev image.
### Verification steps
* build new CI image
```
make ci-build
```
* run dev env
```
make dev
```
* additionally, you can run tests from the container
```
script/ci
```
Co-authored-by: Eguzki Astiz Lezaun <[email protected]>
