RE: Add missing copyright for pg_upgrade/t/* files

Dear Amit,

Thank you for responding!

> 
> Yeah, it is good to have the Copyright to keep it consistent with
> other test files and otherwise as well.
> 
> --- a/src/bin/pg_upgrade/t/001_basic.pl
> +++ b/src/bin/pg_upgrade/t/001_basic.pl
> @@ -1,3 +1,5 @@
> +# Copyright (c) 2022-2023, PostgreSQL Global Development Group
> 
> How did you decide on the starting year as 2022?

I checked the commit log.
About 001_basic.pl, it had been added at 2017 once but been reverted soon [1][2].
322bec added the file again at 2022[3], so I chose 2022.

About 002_pg_upgrade.pl, it has been added at the same time[3]. 
Definitively it should be 2022.

[1]: https://github.com/postgres/postgres/commit/f41e56c76e39f02bef7ba002c9de03d62b76de4d
[2] https://github.com/postgres/postgres/commit/58ffe141eb37c3f027acd25c1fc6b36513bf9380
[3: https://github.com/postgres/postgres/commit/322becb6085cb92d3708635eea61b45776bf27b6

Best Regards,
Hayato Kuroda
FUJITSU LIMITED