Use Go version defined in go.mod for running Go linter action

[jjngx]

Proposed changes

Use explicit Go version (defined in the go.mod file) to run Go linter workflow (GitHub Action - ActionLint). This way we will avoid current dependency issues on Go 1.24.

PR fixes this deps:

run golangci-lint
  Running [/home/runner/golangci-lint-1.63.4-linux-amd64/golangci-lint run] in [/home/runner/work/nginx-prometheus-exporter/nginx-prometheus-exporter] ...
  Error: ../../../go/pkg/mod/golang.org/x/[email protected]/unix/vgetrandom_linux.go:7:9: file requires newer Go version go1.24 (application built with go1.23) (typecheck)
  package unix
          ^
  Error: ../../../go/pkg/mod/golang.org/x/[email protected]/http2/config_go124.go:7:9: file requires newer Go version go1.24 (application built with go1.23) (typecheck)
  package http2
          ^
  
  Error: issues found
  Ran golangci-lint in 23318ms

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING guide
• I have proven my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have ensured the README is up to date
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch on my own fork