Availability Set to VMSS Flex wording fixed

[FallenHoot]

Overview/Summary

While availability sets are not scheduled for immediate deprecation, they are planned to be deprecated in the future. At this time, no date has been confirmed.

Related Issues/Work Items

235 - Fixing wording to make it less confusing

Breaking Changes

1. No breaking changes. End users can decide if they want to do this now or when the deprecation announcement is officially stated.

As part of this pull request I have

• [X] Read the Contribution Guide and ensured this PR is compliant with the guide
• [X] Checked for duplicate Pull Requests
• [X] Associated it with relevant GitHub Issues or ADO Work Items (Internal Only)
• [X] Ensured my code/branch is up-to-date with the latest changes in the main branch
• [NA] Ensured PR tests are passing
• [NA] Performed testing and provided evidence (e.g. screenshot of output) for any changes associated to ARG queries
• [NA] Updated relevant and associated documentation (e.g. Contribution Guide, Docs etc.)

[ejhenry]

Recommendation wording has been verified by PG. We will need to check with DRI and PG before making this change.