…auto run if on… (apache#4214)

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### What changes were proposed in this PR?
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This PR fixes the CI workflow so the “build and push images” job does
not run on every contributor’s branch. The job is now gated with a
job-level condition:

if: github.event_name != 'schedule' || github.repository ==
'apache/texera'

This ensures the job runs for normal (non-scheduled) events, and for
scheduled runs only when the workflow is running in the upstream
apache/texera repository.

### Any related issues, documentation, discussions?
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N/A

### How was this PR tested?
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CI workflow change only. Verified the condition restricts scheduled runs
to apache/texera while allowing non-scheduled events to proceed as
before.

### Was this PR authored or co-authored using generative AI tooling?
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No

Co-authored-by: Chen Li <chenli@gmail.com>
Co-authored-by: Xinyuan Lin <xinyual3@uci.edu>