refactor: update icon cdn domain

[kyubisation]

Our icon CDN is now available at https://icons.app.sbb.ch/.

[jeripeierSBB]

Yeah, LGTM

[codecov-commenter]

Codecov Report

Merging #1847 (6ecbcca) into master (ab917b0) will decrease coverage by 17.41%.
The diff coverage is 34.45%.

❗ Your organization is not using the GitHub App Integration. As a result you may experience degraded service beginning May 15th. Please install the Github App Integration for your organization. Read more.

@@             Coverage Diff             @@
##           master    #1847       +/-   ##
===========================================
- Coverage   54.85%   37.44%   -17.41%     
===========================================
  Files          49      257      +208     
  Lines        1659     9830     +8171     
  Branches      406     2119     +1713     
===========================================
+ Hits          910     3681     +2771     
- Misses        671     5882     +5211     
- Partials       78      267      +189     

Impacted Files	Coverage Δ
...ts/sbb-accordion-item/sbb-accordion-item.events.ts	100.00% <ø> (ø)
.../sbb-accordion-item/sbb-accordion-item.stories.tsx	0.00% <0.00%> (ø)
...mponents/sbb-accordion-item/sbb-accordion-item.tsx	0.00% <0.00%> (-37.21%)	⬇️
...components/sbb-accordion/sbb-accordion.stories.tsx	0.00% <0.00%> (ø)
...ents/sbb-action-group/sbb-action-group.stories.tsx	0.00% <0.00%> (ø)
...onents/sbb-alert-group/sbb-alert-group.stories.tsx	0.00% <0.00%> (ø)
src/components/sbb-alert/sbb-alert.stories.tsx	0.00% <0.00%> (ø)
...onents/sbb-autocomplete/sbb-autocomplete.events.ts	100.00% <ø> (ø)
...ents/sbb-autocomplete/sbb-autocomplete.stories.tsx	0.00% <0.00%> (ø)
src/components/sbb-button/sbb-button.stories.tsx	0.00% <0.00%> (ø)
... and 58 more

... and 201 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more