[YUNIKORN-3073] Upgrade webapp to angular 20

[kousei47747]

What is this PR for?

Upgrade webapp to Angular 20.
For compatibility, Node has been upgraded to 20, and TypeScript to 5.8.
The watch=false flag was added to the test:coverage command to prevent it from getting stuck — likely due to the interaction between Node 20 and Karma.

What type of PR is it?

• - Bug Fix
• - Improvement
• - Feature
• - Documentation
• - Hot Fix
• - Refactoring

What is the Jira issue?

https://issues.apache.org/jira/browse/YUNIKORN-3073

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 35.71%. Comparing base (541135b) to head (1d0eebb).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #234   +/-   ##
=======================================
  Coverage   35.71%   35.71%           
=======================================
  Files           2        2           
  Lines          56       56           
=======================================
  Hits           20       20           
  Misses         33       33           
  Partials        3        3           

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[chenyulin0719]

Hi @kousei47747 , I got an error while building web image. Do you have the same error after running make clean image?

[kousei47747]

Hi @chenyulin0719 thanks for reviewing! It works both on my local and github actions.

[chenyulin0719]

+1 LGTM, image built sucessfully on my Mac.