[FLINK-37151][runtime-web] Remove redundant testing dependencies and files

[Laffery]

JIRA Ticket: issues.apache.org/jira/browse/FLINK-37151

What is the purpose of the change

Remove redundant testing dependencies and testing files, because they are useless.

Brief change log

• remove testing deps such as @testing-library/angular karma jasmine protractor
• remove testing files *.spec.ts
• remove other useless files and configuration

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• bf7cdf3 Azure: SUCCESS

Bot commands

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• @flinkbot run azure re-run the last Azure build

[davidradl]

I am curious why you have made this change - as it is not a removal.

[Laffery]

hi @davidradl , thanks for your review!

This change is an equivalent replacement.
Since angular v17, the polyfills option can be simply set to zone.js if the duty of polyfills.ts is just to importing zone.js.