Remove Date_recur patch as now included in date_recur 3.1

[andybroomfield]

Fix #69

Patch should now be part of drupal/date_recur 3.1+

[finnlewis]

@andybroomfield we're just discussing this in the Tech drop-in call with @ekes and @stephen-cox .

Considering this is blocking https://github.com/benlamptey, we're going to go ahead and merge it and make a release.

[benlamptey]

amazing, thank you all!!