fix: remove tokenFile after production build

[caalador]

Clean the token file after
production build/execution
to not make ide app execution
run app in production mode.

Closes #20294

[sonarqubecloud]

Quality Gate passed

Issues
86 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

Test Results

1 142 files  + 1  1 142 suites  +1   1h 27m 27s ⏱️ + 2m 56s
7 474 tests + 1  7 424 ✅ ± 0  50 💤 +1  0 ❌ ±0 
7 847 runs  +24  7 787 ✅ +23  60 💤 +1  0 ❌ ±0 

Results for commit 8b262c1. ± Comparison against base commit 55efd4e.

[tltv]

Removal of the token file after build-frontend would also mean one can't run the app in production mode directly by running Spring application class in IDE.
I don't see anything in documentation telling that it should be possible so therefore it should be OK. Running with maven/gradle or running the package directly still works as usual.

A test would be good however.

[caalador]

The issue with the test is just that it should check that the file is missing after the JVM closes.
BuildFrontendUtilTest in flow-plugin-base contains lots of tests that the token file exists and that it updates the file contents correctly.

[vaadin-bot]

This ticket/PR has been released with Vaadin 24.6.0.alpha2 and is also targeting the upcoming stable 24.6.0 version.