fix: not generate selector of deployment/daemonset based on the custom label configuration of EnvoyProxy

[sanposhiho]

What type of PR is this?

What this PR does / why we need it:

The selector on Deployment and Daemonset is immutable.
We currently generate the selector based on a custom label config of envoy proxy (i.e., the input from users) and users can change the config anytime.
So, if users make such changes, the reconciliation tries to update the selector too, and fails (#1818 #3666).

This PR makes the selector of Deployment and Daemonset stable, generating it without the custom labels.
But, if we just do that, it could result in the breaking change to existing users who already has a deployment / daemonset with a custom label (because the envoy gateway of new version tries to eliminate the custom label from the selector)

So, in order not to introduce such breaking changes, this PR tries to always keep the selector of existing deployment or daemonset.
So, all new deployment and daemonset will have a selector generated without the custom labels, and all existing ones will keep a selector generated with or without the custom labels.
It also means we only help future users; we don't help existing users who already have a deployment/daemonset created with a custom label and want to change the custom label. They should recreate envoyproxy by themselves to recreate the underlying deployment/daemonset. (We don't implement such recreation because it's not a fair deal to implement/maintain a complicated safe recreation process for such a few users.)

Which issue(s) this PR fixes:

Fixes #1818 #3666

[codecov]

Codecov Report

Attention: Patch coverage is 80.95238% with 8 lines in your changes missing coverage. Please review.

Project coverage is 67.66%. Comparing base (bd26a41) to head (5ef25a5).
Report is 6 commits behind head on main.

Files	Patch %	Lines
...ternal/infrastructure/kubernetes/infra_resource.go	74.19%	5 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3995      +/-   ##
==========================================
+ Coverage   67.61%   67.66%   +0.05%     
==========================================
  Files         186      186              
  Lines       22757    22785      +28     
==========================================
+ Hits        15387    15418      +31     
+ Misses       6266     6263       -3     
  Partials     1104     1104              

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[zirain]

/retest

[arkodg]

LGTM thanks !

[zirain]

/retest