chore(deps): update centos docker tag to v8 (builds-1.1) (#253)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| centos | final | major | `7` -> `8` |

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR has been generated by [Renovate
Bot](https://togithub.com/renovatebot/renovate).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOC41NS4yLXJwbSIsInVwZGF0ZWRJblZlciI6IjM4LjU1LjItcnBtIiwidGFyZ2V0QnJhbmNoIjoiYnVpbGRzLTEuMSIsImxhYmVscyI6W119-->

openshift-ci/Dockerfile.tools

@@ -2,7 +2,7 @@
 # 
 # SPDX-License-Identifier: Apache-2.0
 
-FROM centos:7 as build-tools
+FROM centos:8 as build-tools
 ENV LANG=en_US.utf8
 ENV GOPATH /tmp/go
 ARG GO_PACKAGE_PATH=github.com/shipwright-io/build