Remove the "run extended tests" github PR commend action

[alamb]

Which issue does this PR close?

• Follow on to Add a way to trigger the extended test suite from a PR #14319
• Reverts Triggering extended tests through PR comment: Run extended tests #15101
• Reverts Add documentation for Run extended tests command #15463

Rationale for this change

@danila-b made a very cool set of github runner workflows to run the extended tests on demand on CI. The idea was that
it could be used to run the extended tests on each PR that might cause breakages before merging to main.

However, in practice it seems it is not used much and hasn't stopped regressions
as we had hoped. For example here are some recent issues that were closed that
mentioned extended tests where extended tests broke after merging to main even
after the run extended tests command was added (on Mar 27, 2025):

• extended tests failing on main (External error: query is expected to fail, but actually succeed:) #15641
• Extended tests are failing #16595
• CI failure on Datafusion extended tests / cargo test hash collisions (amd64) (push) #16378

I think the challenge is twofold:

1. It is not obvious when to run the extended tests
2. It is not obvious the result of the extended tests (it is reported as a Labeler check, which is not very visible -- see Add partial_sort.slt test for partially sorted data #16900 (comment) for an example)

I am sure we could the second point, but the first remains very hard.

Also, the complexity of the extended workflow makes it harder to understanding
and maintain and verify the security of the CI workflows in general.

Thus, I think it is best to remove the extended github comment workflow for now.

What changes are included in this PR?

1. Remove the github extended workflow

Are these changes tested?

I tested it manually

Are there any user-facing changes?

Less PR automation

[alamb]

run extended tests

[alamb]

run extended tests

I don't expect this to do anything, but. want to verify that is the case

[timsaucer]

Thank you, Andrew. This seems reasonable to disable based on the discussion and the limited benefit it has shown.

[comphead]

Thanks @alamb

[alamb]

Here is another example of extended tests failing on main without us catching it

• Simplify comparisons and binary operations involving NULL #17088

😢

[comphead]

Here is another example of extended tests failing on main without us catching it

• Simplify comparisons and binary operations involving NULL #17088

😢

WDYT if we enforce extended tests on RC branch-* branches?

[alamb]

Here is another example of extended tests failing on main without us catching it

• Simplify comparisons and binary operations involving NULL #17088

😢

WDYT if we enforce extended tests on RC branch-* branches?

Sounds good to me

[alamb]

Thank you @timsaucer and @comphead

[Omega359]

😢