azurerm_key_vault data source: cache the vault_uri once read

[magodo]

Mitigate #11059.

THe listing resources API won't be called if the keyVaultCache is populated. Currently, the cache is populated in following places (prior to calling the resource listing API):

• When the key vault resource is created
• When the key vault resource is read

The reports in #11059 are mostly happening when the depending key vault is a data source. This PR adds support for that use case.

In result, as long as users guarantee the correct dependency between key vault (either resource or data source) and the nested items, then the listing resource API is avoided.

[tombuildsstuff]

LGTM 👍

[elongstreet88]

Thanks @tombuildsstuff !
Is it possible to prioritize releasing 3.12.0 sooner than later for this fix in particular?
Assuming this resolves what we think its supposed to, our build performance will probably 10x back to what it used to.

[github-actions]

This functionality has been released in v3.12.0 of the Terraform Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active contributions.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.