feat(ci): Add build image job for PR checks

[anurag-rajawat]

Description

Fix the docker-buildx target to fail with an error if the build fails. Additionally, add a new job to the PR checks that builds the operator's docker image to ensure it can be built successfully before merging the PR.

Fixes # (issue)

Does this PR introduce a breaking change?
No

Checklist

• PR title follows the <type>: <description> convention
• I use conventional commits in my commit messages
• I have updated the documentation accordingly
• I Keep It Small and Simple: The smaller the PR is, the easier it is to review and have it merged
• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Additional information for reviewer

Mention if this PR is part of any design or a continuation of previous PRs

First merge this PR because it has a commit to fix the Dockerfile