Switch to the new API for marking as required the region field of the Cloud Function resource

[trampfox]

Description of your changes

This PR switches to the new config.Resource.MarkAsRequired to mark as required the region field of the Cloud Function resource.

Fixes #575

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

[jeanduplessis]

/test-examples="examples/cloudfunctions/v1beta2/function.yaml"

[turkenf]

Hey @trampfox, thanks for the fix. The change looks good to me, but it would be good if you add the manual test results to the description before continuing. The resource's uptest skipped because it contains manual-intervention. So, can you test manually and verify that the problem is gone

[clarkritchie]

Chiming in to provide moral support on merging this one.

[turkenf]

Hi @clarkritchie, thank you for your interest. Are you willing to test the resource manually?

[clarkritchie]

@turkenf Sure thing, apologies that I missed your comment.

[turkenf]

@clarkritchie, could you please test with the following:

apiVersion: pkg.crossplane.io/v1
kind: Provider
metadata:
  name: provider-gcp-cloudfunctions
spec:
  package: index.docker.io/turkenf/provider-gcp-cloudfunctions:v1.6.0-rc.0.15.g34ea968e1

[chakrii]

@turkenf I can confirm CloudFunction creation is working when pointing to package: index.docker.io/turkenf/provider-gcp-cloudfunctions:v1.6.0-rc.0.15.g34ea968e1
Failure
Provider pointing xpkg.upbound.io/upbound/provider-gcp-cloudfunctions:v1.0.2

Success
Provider pointing to package: index.docker.io/turkenf/provider-gcp-cloudfunctions:v1.6.0-rc.0.15.g34ea968e1

[clarkritchie]

Awesome, thank you @chakrii!

[turkenf]

@chakrii, thank you for sharing results,I couldn't quite understand from the screenshots you shared, does the issue go away even if the provider is not healthy?

Edit: Ahh, I just saw that the config package is unhealthy

[chakrii]

@chakrii, thank you for sharing results,I couldn't quite understand from the screenshots you shared, does the issue go away even if the provider is not healthy?

Edit: Ahh, I just saw that the config package is unhealthy

@turkenf Config package is unhealthy but at least the CloudFunction got created and no longer seeing issue.

[turkenf]

Thanks for your patience and interaction here, folks. LGTM.