fix(ci): [agent6] Remove unecessary jobs

[chouetz]

What does this PR do?

Remove some unnecessary non-generated jobs from the deploy_dca stage as I suspect they are causing the trigger_release jobs to be skipped on the Agent 6 RC pipeline (see example)

Looking on the pipeline configuration, the rule is not preventing this to run

Waiting until the 6.53.1-rc.3 tag appears in Gitlab
Creating RC pipeline
Creating pipeline for datadog-agent on branch/tag 6.53.1-rc.3 with args:
  - DEPLOY_AGENT: true
  - RUN_ALL_BUILDS: true
  - RUN_E2E_TESTS: on
  - RUN_KMT_TESTS: on
  - RELEASE_VERSION_6: release-a6
  - RELEASE_VERSION_7: release-a7
  - BUCKET_BRANCH: beta
  - RC_BUILD: true

so I think it could come from these jobs not launched and required because there is no explicit needs on these jobs.

Motivation

Automatic generation of the job is better than running it manually

Describe how you validated your changes

Possible Drawbacks / Trade-offs

Additional Notes

[pr-commenter]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=51080452 --os-family=ubuntu