Fixed builds when a package has dependencies on other branches

[mnocon]

Current situation:
When the composer.json is modified to include dependencies on other branches then the dependencies.json is not enough to run the Browser tests - the build will fail before the file is even parsed.

This PR moves the parsing of dependencies.json before the Ibexa main package (oss, headless, experience, commerce) is added so that Composer is aware that additional dev packages will be needed.

Example failure:
https://github.com/ibexa/rest/actions/runs/7287087802/job/19857028341?pr=82

TODO:

1. Check that it works in normal regression builds
2. Check that it works when a PR with modified composer.json is included in a regression
3. Copy the solution to other scripts (3.3, 4.5)

[sonarcloud]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[mnocon]

This is broken on 4.6 only, because of these PRs:
#76
#73

So:

1. Dependencies should be added after behat and docker, to allow overwriting them
2. Dependencies should be added before the Ibexa package, to stop the changes from package's composer.json from failing the build
3. docker should be added after the Ibexa package, otherwise Moved ibexa/behat and ibexa/docker installation #73 happens

looks like an order like this is not possible - and another solution would be needed.

Closing this one, it needs another approach