add queueing_method to cloudflare_waiting_room

[broswen]

Add a queueing_method property to cloudflare_waiting_room resource.

This is already publicly documented. https://api.cloudflare.com/#waiting-room-create-waiting-room

[github-actions]

changelog detected ✅

[jacobbednarz]

acceptance tests are good

TF_ACC=1 go test $(go list ./...) -v -run "^TestAccCloudflareWaitingRoom_" -count 1 -parallel 1 -timeout 120m -parallel 1

=== RUN   TestAccCloudflareWaitingRoom_Create
=== PAUSE TestAccCloudflareWaitingRoom_Create
=== CONT  TestAccCloudflareWaitingRoom_Create
--- PASS: TestAccCloudflareWaitingRoom_Create (8.88s)
PASS
ok      github.com/cloudflare/terraform-provider-cloudflare/internal/provider   9.661s
?       github.com/cloudflare/terraform-provider-cloudflare/tools/cmd/changelog-check   [no test files]
?       github.com/cloudflare/terraform-provider-cloudflare/tools/cmd/maintainer-only-file-check        [no test files]
?       github.com/cloudflare/terraform-provider-cloudflare/tools/cmd/tf-log-check      [no test files]
?       github.com/cloudflare/terraform-provider-cloudflare/version     [no test files]

[github-actions]

This functionality has been released in v3.19.0 of the Terraform Cloudflare 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!