Switch to sassc-rails

Closes #18432

See merge request !8556

Closes #18432

This uses sassc to compile the application's SASS so it compiles faster.

Without attempting to be very scientific here are some numbers I got:

Using sassc-rails:

```
[1] pry(main)> Benchmark.bm { |bm| bm.report { Rails.application.assets["application.css"] } }
       user     system      total        real
   1.430000   0.380000   1.810000 (  1.830753)
```

Using sass-rails:
```
[1] pry(main)> Benchmark.bm { |bm| bm.report { Rails.application.assets["application.css"] } }
       user     system      total        real
  12.320000   0.530000  12.850000 ( 12.909684)
```

The result is faster page loads when changing CSS in development and
faster precompilation.

Remove rerun since it's not used anymore

Closes #19633

See merge request !8598

Synchronize all project authorization refreshing work using a lease

Closes #25987

See merge request !8599

Fixed random issue boards sidebar failure

Closes #26751

See merge request !8602

Update ffaker to ~>2.4 to avoid generating names with suffixes

Closes #26492

See merge request !8596

Previously a lease would only be obtained to update data. This could
lead to duplicate data being inserted, triggering a UNIQUE constraint
error. To work around this we now acquire a lease before performing
_any_ project authorization work, releasing it at the very end.

Fixes #25987

Signed-off-by: Rémy Coutable <remy@rymai.me>

Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix search group/project filtering to show results

Closes #26616

See merge request !8565

Pipeline Index Mini Graph Fix

See merge request !8542

Ensure updating project settings shows a flash message on success

See merge request !8579

Resolve "Add Hover animations"

Closes #26207

See merge request !8415

Retain original casing for  build name in manual pipeline dropdown

Closes #25946

See merge request !8387

Yet another dot git migration fix

See merge request !8592

Remove Lock Icon on Protected Tag

Closes #22111

See merge request !8513

Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix issue with diff comments path

See merge request !7819

Remove margin on mobile links

Fix migration failing when user has no projects

See merge request !8589