Upgrade jQuery to 3.6.0.

[dracos]

Upgrading to jQuery 2.2.4 (+3.5.0 security patch) was done in #3017 after I took this commit out so the change wasn't as big.

I think only a couple of changes here are actually needed (e.g. complete to always), the others are warnings given by jquery migrate but still work fine, so if any have been missed it shouldn't matter (hopefully haven't though). The :first/:last/etc selectors were deprecated in 3.4 but still working (currently scheduled to be removed in 4, I think). But e.g. first() is quicker than :first so no harm in doing these. click() etc were technically deprecated in 3.3 - https://blog.jquery.com/2018/01/19/jquery-3-3-0-a-fragrant-bouquet-of-deprecations-and-is-that-a-new-feature/ - but the docs still don't say they are and there are frequent issues on the migrate repo saying why does it warn and they say "PR the docs" and have been since at least 2018, so who knows what's happening there. Again, no harm in switching now though.

[codecov]

Codecov Report

Merging #3442 (d665128) into master (af6eed1) will decrease coverage by 10.42%.
The diff coverage is 79.80%.

❗ Current head d665128 differs from pull request most recent head 6063020. Consider uploading reports for the commit 6063020 to get more accurate results

@@             Coverage Diff             @@
##           master    #3442       +/-   ##
===========================================
- Coverage   82.64%   72.21%   -10.43%     
===========================================
  Files         345       51      -294     
  Lines       23662     4384    -19278     
  Branches     3608        0     -3608     
===========================================
- Hits        19555     3166    -16389     
+ Misses       2973     1218     -1755     
+ Partials     1134        0     -1134     

Impacted Files	Coverage Δ
web/cobrands/fixmystreet/offline.js	45.02% <0.00%> (ø)
web/js/duplicates.js	62.50% <0.00%> (ø)
web/js/map-OpenLayers.js	77.24% <25.00%> (-0.17%)	⬇️
web/cobrands/fixmystreet/fixmystreet.js	73.84% <84.93%> (+0.64%)	⬆️
web/cobrands/fixmystreet/admin.js	18.10% <87.50%> (ø)
web/cobrands/fixmystreet/staff.js	55.95% <91.66%> (ø)
web/cobrands/bromley/a-z-nav.js	50.00% <100.00%> (ø)
web/cobrands/fixmystreet.com/js.js	72.72% <0.00%> (-9.10%)	⬇️
web/cobrands/fixmystreet-uk-councils/alloy.js	88.11% <0.00%> (-2.98%)	⬇️
... and 297 more

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[dracos]

@zarino you already reviewed this last year, and the 2.2 part of that is live now, so this is just the 3 changes, which aren't anything much it seems.

[zarino]

Looks good to me.

I notice lots of changes inside web/vendor/fancybox/jquery.fancybox-1.3.4.js. Should we just be using the latest version (3.5.7) of fancybox instead?

[dracos]

That version is only available under a non-commercial licence. I think on the old PR I did say someone should go and evaluate all the new JS packages out there and pick the smallest new one to switch to :)

[zarino]

Yup, not a dealbreaker. Just thought I’d check we had a reason for not using the latest. Agree it’s something we can sort in a subsequent PR.