pgsql: Fix .gitignore for src/interfaces/libpq-oauth.

On Fri, Aug 29, 2025 at 9:06 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:

Fix .gitignore for src/interfaces/libpq-oauth.

This missed files created when running the oauth tests.

Thanks for the fix!

Branch
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REL_18_STABLE

Note that 18 doesn't have a `check` target yet -- I backported the
build fixes, but not the test suite itself. (That doesn't seem to have
any stability problems so far, so it probably makes sense for me to
backport it soon.)

--Jacob