Use trashcan icon for remove review request

[jpraet]

Fixes #13721

Changes the icon for "Remove review request" from octicon-sync to octicon-trashcan.

[codecov-io]

Codecov Report

Merging #13722 (996f550) into master (979fbe0) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #13722      +/-   ##
==========================================
- Coverage   42.25%   42.24%   -0.02%     
==========================================
  Files         697      697              
  Lines       76631    76631              
==========================================
- Hits        32384    32376       -8     
- Misses      38925    38933       +8     
  Partials     5322     5322              

Impacted Files	Coverage Δ
modules/util/timer.go	42.85% <0.00%> (-42.86%)	⬇️
modules/charset/charset.go	68.53% <0.00%> (-4.50%)	⬇️
services/pull/temp_repo.go	26.59% <0.00%> (-3.20%)	⬇️
services/pull/patch.go	53.97% <0.00%> (-1.71%)	⬇️
services/pull/check.go	48.90% <0.00%> (ø)
services/pull/pull.go	41.17% <0.00%> (+0.49%)	⬆️
models/gpg_key.go	53.90% <0.00%> (+0.57%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 979fbe0...996f550. Read the comment docs.