Clear backend cache when purging the updates

[zero-24]

Summary of Changes

Clear backend cache when purging the updates

Testing Instructions

• enable caching
• apply this patch
• got to com_installer -> updates
• hit clear cache
• check the administrator/cache/_system folder creation dates of the files it should be a fresh version.

Expected result

now also the backend caches are cleared

Actual result

right now the backend caches are not cleared.

Documentation Changes Required

none

Mentions

@nikosdion sorry that it took that long to get back to you on this. Please confirm that this is what you had in mind regarding that method. The other two things truncate #__updates and set the last check to zero is already done in the existing code.

[nikosdion]

Yes, that's basically what I found out I had to do every time I was purging existing updates. This also meshes with my experience in previous bug sprints when I had to do the same thing every time a plugin was edited / published / unpublished.

Also: yup, that's one positive test in case it wasn't clear. Sorry, my coffee needs more coffee today...

[richard67]

Also: yup, that's one positive test in case it wasn't clear. Sorry, my coffee needs more coffee today...

@nikosdion Does that mean you have tested this PR here with success? If so, could you mark your result in the issue tracker, or shall I do that for you? Or did I get the above wrong and it was not a test of this PR?

[Quy]

I have tested this item ✅ successfully on aa3cfe6

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[richard67]

I have tested this item ✅ successfully on aa3cfe6

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[richard67]

RTC

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[wilsonge]

Thanks guys!