[SPARK-48116][INFRA][FOLLOWUP] Fix if statement to check repository

[dongjoon-hyun]

What changes were proposed in this pull request?

This is a follow-up of the following to fix if statement.

• [SPARK-48116][INFRA] Run pyspark-pandas* only in PR builder and Daily Python CIs #46367

Why are the changes needed?

Currently, master branch works like the following.

https://github.com/apache/spark/actions/runs/8947915962/job/24580432178

It was a mistake to use string evaluation type which goes to then statement as a result.

    if [ "false" ]; then
      pandas=$pyspark
    else
      pandas=false
    fi

Like the following, this PR fixes if statement.

spark/.github/workflows/build_and_test.yml

Line 269 in 1904dee

if [[ "$MODULES_TO_TEST" == "hive" ]] && [[ "$EXCLUDED_TAGS" == "org.apache.spark.tags.SlowHiveTest" ]]; then export METASPACE_SIZE=2g; fi

The following is the new result on this PR Builder.

    if [[ "dongjoon-hyun/spark" != 'apache/spark' ]]; then
      pandas=$pyspark
    else
      pandas=false
    fi

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Manual review.

Was this patch authored or co-authored using generative AI tooling?

No.

[HyukjinKwon]

@dongjoon-hyun Can we maybe just merge #46380 instead?

[dongjoon-hyun]

Of course.

[HyukjinKwon]

LGTM. I cherry-picked this instead.