[SPARK-28342][SQL][TESTS] Replace REL_12_BETA1 to REL_12_BETA2 in PostgresSQL SQL tests

[HyukjinKwon]

What changes were proposed in this pull request?

This PR proposes to replace REL_12_BETA1 to REL_12_BETA2 which is latest.

How was this patch tested?

Manually checked each link and checked via git grep -r REL_12_BETA1 as well.

[HyukjinKwon]

@dongjoon-hyun, seems actually there's no diff to make in Spark SQL files. I was referring this diff postgres/postgres@44e95b5 but that's not in Spark yet ..

[HyukjinKwon]

cc @wangyum too

[dongjoon-hyun]

Cool! Thank you for confirming. It cleans up my mind. :)

[wangyum]

Thank you @HyukjinKwon

[dongjoon-hyun]

+1, LGTM. (I checked f90660a).

Now, there is no remaining REL_12_BETA1.
Merged to master (since these are all comments and output files are unchanged.)

[HyukjinKwon]

Thank you guys!

[SparkQA]

Test build #107499 has finished for PR 25105 at commit f90660a.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #107497 has finished for PR 25105 at commit afb2862.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.