Don't immediately delete PR's branch in case it's close&reopen

[Jackenmen]

Fixes #70

Alternatively, we could create a task and add a listener for reopen that will cancel the existing task if one exists.

[Jackenmen]

After a second thought, perhaps the sleep should be lower? Like 15 seconds?

[Jackenmen]

I have to update tests here.

[codecov]

Codecov Report

Merging #483 (9498225) into main (8569d62) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main      #483   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           10        10           
  Lines          983      1009   +26     
  Branches        69        71    +2     
=========================================
+ Hits           983      1009   +26     

Impacted Files	Coverage Δ
miss_islington/delete_branch.py	100.00% <100.00%> (ø)
tests/test_delete_branch.py	100.00% <100.00%> (ø)

[Jackenmen]

I have to update tests here.

Done.

[Mariatta]

I think this is a great solution.
Thank you!