Integrate seco-build-configurator/lpag/fix_submodule and 2 more

Commit: clea-os/tools/seco-build-configurator@2ec59198

[CICD] Update 'gitlab-ci' revision to the latest avaialable

• The 'scarthgap-dev' branch was misaligned from the CI state of the art because the integration of 'gitlab-ci' modification is working only on 'scarthgap' branches.
• Change submodule paths to relative paths as per CI requirement (see https://git.seco.com/clea-os/infrastructure/gitlab-ci/-/blob/master/docs/add-new-project-to-pipeline.md?ref_type=heads#add-submodule-gitlab-ci)

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Commit: clea-os/tools/seco-build-configurator@e4c307fd

[CICD] Change MAIN_BRANCH variable value to 'scarthgap'

The development branch 'scarthgap-dev' has been migrated to the production one and thus CI/CD need to be changed accordingly.

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Commit: clea-os/tools/seco-build-configurator@8ddc465f

Bump to version 2.0.0

Changelog:

• [CLUSTER][CORE][TESTS] Add cluster adding variables with :append (ref: 509339f)