Replace references to upbound/uptest reusable workflows to upbound/official-providers-ci

[jbw976]

Description of your changes

This PR cherry-picks the commit from crossplane/upjet-provider-template#64 and applies it to this repository.

Please see the description of that PR for context/details of this. I encountered the below error when running the Tag workflow in https://github.com/crossplane-contrib/provider-okta/actions/runs/9453981739 and realized that PR crossplane/upjet-provider-template#64 should fix this for us 🙏

error parsing called workflow ".github/workflows/tag.yaml" -> "upbound/uptest/.github/workflows/provider-tag.yml@main"

For posterity, I ran the following commands to cherry-pick the commit from a different repo:

git remote add patch-origin https://github.com/crossplane/upjet-provider-template.git
git fetch --all
git checkout -b update-workflows upstream/main
git --git-dir=../../crossplane/upjet-provider-template/.git format-patch -k -1 979663be8dc10b1dbabed011a7009a1e994d8077 --stdout | git am -3 -k --ignore-whitespace

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

This will be tested within the github actions during the next v0.3.0 release, which we're trying to get out today 😇

[jbw976]

@rjop-hccgt if you want to take a look at this one so I can keep making progress on the v0.3.0 release 🙏

[rjop-hccgt]

LGTM!

[github-actions]

Successfully created backport PR #7 for release-0.3.