ci: extend Konflux docs-only skip to match Prow skip rules (#642)

Extend the CEL expression in Tekton PipelineRun definitions to also skip
Konflux builds when only `.gitignore`, `OWNERS`, `PROJECT`, `LICENSE`,
.`github/`, or `.tekton/` files are changed — matching the existing
skip_if_only_changed regex used by the Prow ci-operator jobs.

An example of the existing prow ci-operator job skip condition:
```yaml
skip_if_only_changed: ^docs/|\.md$|^(?:.*/)?(?:\.gitignore|OWNERS|PROJECT|LICENSE|CONTRIBUTING\.md)$|^\.github/|^\.tekton/
```
-
https://github.com/openshift/release/blob/01591970ea5008bda7b05a49ce8a0905207182ee/ci-operator/jobs/opendatahub-io/models-as-a-service/opendatahub-io-models-as-a-service-main-presubmits.yaml#L21

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

* **Chores**
* Updated pull request pipeline triggering conditions to exclude
additional configuration files and CI/CD directories from initiating
automated checks.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: mynhardtburger

.tekton/odh-maas-controller-pull-request.yaml

@@ -11,7 +11,7 @@ metadata:
     pipelinesascode.tekton.dev/on-cel-expression: event == "pull_request" && target_branch
       == "main" && !files.all.all(x, x.matches('^docs/') || x.matches('\\.md$')
       || x.matches('^(.*/)?(\\.gitignore|OWNERS|PROJECT|LICENSE)$')
-      || x.matches('^\\.github/'))
+      || x.matches('^\\.github/') || x.matches('^\\.tekton/'))
   creationTimestamp: null
   labels:
     appstudio.openshift.io/application: opendatahub-builds