Update k8s to 1.36 and build with go 1.26

[ceriath]

This is a follow up to #1921 (including its changes) adding support for k8s 1.36 (which required go 1.26)

[aryan9600]

ci is failing because we also need to update the go version in the actions yaml

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 0% with 490 lines in your changes missing coverage. Please review.
✅ Project coverage is 29.78%. Comparing base (cd964bb) to head (122fe97).
⚠️ Report is 19 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/client/informers/externalversions/factory.go	0.00%	30 Missing ⚠️
...nformers/externalversions/apisix/v2/apisixroute.go	0.00%	20 Missing ⚠️
...informers/externalversions/appmesh/v1beta1/mesh.go	0.00%	20 Missing ⚠️
...rs/externalversions/appmesh/v1beta1/virtualnode.go	0.00%	20 Missing ⚠️
...externalversions/appmesh/v1beta1/virtualservice.go	0.00%	20 Missing ⚠️
...rs/externalversions/appmesh/v1beta2/virtualnode.go	0.00%	20 Missing ⚠️
.../externalversions/appmesh/v1beta2/virtualrouter.go	0.00%	20 Missing ⚠️
...externalversions/appmesh/v1beta2/virtualservice.go	0.00%	20 Missing ⚠️
.../externalversions/flagger/v1beta1/alertprovider.go	0.00%	20 Missing ⚠️
...formers/externalversions/flagger/v1beta1/canary.go	0.00%	20 Missing ⚠️
... and 14 more
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Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1922      +/-   ##
==========================================
- Coverage   30.18%   29.78%   -0.41%     
==========================================
  Files         288      288              
  Lines       18533    18591      +58     
==========================================
- Hits         5594     5537      -57     
- Misses      12204    12325     +121     
+ Partials      735      729       -6     

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[ceriath]

regarding codecov: that is generated code and didn't have testing before either