fix(frontend): 画面サイズが変わった際にnavbarが自動で折りたたまれない問題を修正

[kakkokari-gtyih]

What

画面幅の評価をウィンドウのリサイズ時にも行うように
（起動時の１度だけしか評価されないようになっていたため）

Why

Fix #14983 (comment)

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 19.14%. Comparing base (04b2214) to head (10ed8b0).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
packages/frontend/src/ui/_common_/navbar.vue	0.00%	12 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           develop   #15042       +/-   ##
============================================
- Coverage    39.95%   19.14%   -20.81%     
============================================
  Files         1563      728      -835     
  Lines       197739   103800    -93939     
  Branches      3625      993     -2632     
============================================
- Hits         79012    19876    -59136     
+ Misses      118154    83368    -34786     
+ Partials       573      556       -17     

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[syuilo]

🙏🏻