Added: support for multiple network interfaces in openstack datasource

[mklejn-ovh]

Proposed Commit Message

fix(openstack): Support mixed dhcp and no-dhcp interfaces

DS OpenstackLocal was only using fallback_interface for it's metadata service detection
which may fail when multiple interfaces, including ones without dhcp, are provided.
Behaviour fixed via iterating over all interfaces until we hit one that has dhcp enabled,
or we fail to find one and explicitly explain that no interface was able to get dhcp lease.

Fixes GH-6786

Additional Context

Right here: GH-6786

Test Steps

Right here: GH-6786

Merge type

• Squash merge using "Proposed Commit Message"
• Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)