fix(yaml): Don't rely on zfs being in sh's default PATH

[w4]

Why is this PR required? What issue does it fix?:

Fixes usage of zfs-localpv on NixOS/derivative hosts where zfs lives somewhere other than sh's default PATH.

What this PR does?:

Sources /etc/profile before attempting to call zfs

Does this PR require any upgrade changes?:

No

If the changes in this PR are manually verified, list down the scenarios covered::

• Tested on Ubuntu
• Tested on NixOS

Checklist:

• [x] Fixes #
  • n/a
• [x] PR Title follows the convention of <type>(<scope>): <subject>
• [x] Has the change log section been updated?
• [x] Commit has unit tests
• [x] Commit has integration tests
• [ ] (Optional) Are upgrade changes included in this PR? If not, mention the issue/PR to track:
• [ ] (Optional) If documentation changes are required, which issue on https://github.com/openebs/openebs-docs is used to track them:

[pawanpraka1]

@w4 can you DCO sign this PR?

[sinhaashish]

Awaited for the response for long and closing this as its a stale PR . @w4 please raise a different PR , if you need this change Thanks.