VAULT-31184: Support identity token auth in data_artifactory_item

[ryancragun]

How to read this pull request

The primary motivation for this PR is to add support for identity token auth to the artifactory_item datasource. This will allow us to migrate from API auth to identity token auth. We maintain backwards compatibility with API auth and do not change any schema, except for username no longer being required. If no username is provided we assume token that is required is for identity token auth, not API auth.

Note

Since this is a repo in the forge and public we cannot utilize the doormat action to test token auth in CI. As such, I've tested both the artifactory package and the datasource ACC tests locally using both identity token and API auth.

We also do a bit of housekeeping and update our Go modules and pin to the latest Github actions.

Note

We are currently behind on terraform-plugin-go as the server interface now requires implementing provider functions, which we have not done yet.

Checklist

• The commit message includes an explanation of the changes
• Manual validation of the changes have been performed (if possible)
• New or modified code has requisite test coverage (if possible)
• I have performed a self-review of the changes
• I have made necessary changes and/or pull requests for documentation
• I have written useful comments in the code
• Version file/release label updated, if release needed

[anwittin]

Looks good