Add Github workflow that adds backport_failed label when automatic backports fail.

[alinabuzachis]

SUMMARY

Add Github workflow that adds backport_failed label when automatic backports fail.
This will help keep track of any failed backported PRs that require manual actions to be taken.

ISSUE TYPE

• Bugfix Pull Request
• Docs Pull Request
• Feature Pull Request
• New Module Pull Request

COMPONENT NAME

ADDITIONAL INFORMATION

[softwarefactory-project-zuul]

Build succeeded.
https://ansible.softwarefactory-project.io/zuul/buildset/7dd0d0cb9d894dc89d49e0c053176364

✔️ ansible-galaxy-importer SUCCESS in 3m 48s (non-voting)
✔️ build-ansible-collection SUCCESS in 10m 02s

[softwarefactory-project-zuul]

Build succeeded.
https://ansible.softwarefactory-project.io/zuul/buildset/9f03968fc45a4866ae72a09f3c4f0df2

✔️ ansible-galaxy-importer SUCCESS in 3m 15s (non-voting)
✔️ build-ansible-collection SUCCESS in 10m 21s

[softwarefactory-project-zuul]

Build succeeded.
https://ansible.softwarefactory-project.io/zuul/buildset/2d727594dff14f0c9b00ac5ed56d759a

❌ ansible-galaxy-importer FAILURE in 4m 07s (non-voting)
✔️ build-ansible-collection SUCCESS in 10m 20s

[softwarefactory-project-zuul]

Build succeeded.
https://ansible.softwarefactory-project.io/zuul/buildset/61d7f6cebc4e4763aed0a46e404a090b

❌ ansible-galaxy-importer FAILURE in 4m 18s (non-voting)
✔️ build-ansible-collection SUCCESS in 10m 13s

[softwarefactory-project-zuul]

Build succeeded (gate pipeline).
https://ansible.softwarefactory-project.io/zuul/buildset/65ad624d8cbc46049444d80f16161f73

❌ ansible-galaxy-importer FAILURE in 4m 10s (non-voting)
✔️ build-ansible-collection SUCCESS in 10m 06s

[softwarefactory-project-zuul]

Pull request merge failed: Resource not accessible by integration, You may need to manually rebase your PR and retry.