[supervisor] fix caching Not Found as OTS token

[akosyakov]

What it does

Gitpod Server OTS token expires after some time. If the workspace startup takes a while for some reasons then the supervisor gets Not Found, but since it does not check http status code it cached Not Found as a token. Triggering all kind of frontend issues consequently:

How to test

Not sure. Expiration time is quite high, I don't understand how supervisor manages to miss the token.

[codecov]

Codecov Report

Merging #4577 (3127021) into main (5f45aa7) will increase coverage by 36.63%.
The diff coverage is 0.00%.

@@            Coverage Diff            @@
##           main    #4577       +/-   ##
=========================================
+ Coverage      0   36.63%   +36.63%     
=========================================
  Files         0       15       +15     
  Lines         0     3775     +3775     
=========================================
+ Hits          0     1383     +1383     
- Misses        0     2277     +2277     
- Partials      0      115      +115     

Flag	Coverage Δ
components-supervisor-app	36.63% <0.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
components/supervisor/pkg/supervisor/config.go	4.51% <0.00%> (ø)
components/supervisor/pkg/supervisor/services.go	25.70% <0.00%> (ø)
components/supervisor/pkg/ports/served-ports.go	76.00% <0.00%> (ø)
components/supervisor/pkg/ports/ports-config.go	79.85% <0.00%> (ø)
components/supervisor/pkg/supervisor/supervisor.go	0.00% <0.00%> (ø)
...mponents/supervisor/pkg/supervisor/notification.go	83.95% <0.00%> (ø)
components/supervisor/pkg/supervisor/tasks.go	47.97% <0.00%> (ø)
components/supervisor/pkg/ports/tunnel.go	63.63% <0.00%> (ø)
components/supervisor/pkg/dropwriter/dropwriter.go	73.46% <0.00%> (ø)
components/supervisor/pkg/ports/ports.go	61.53% <0.00%> (ø)
... and 6 more

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