ci(.github): update Go integration and vet script

[JoeWang1127]

This change modifies Librarian to modernize the Go integration workflow by updating the vet.sh script to use golangci-lint instead of standalone tools.

The vet.sh script is updated to run golangci-lint with the revive and staticcheck linters.
It now includes robust filtering for known upstream issues in google-cloud-go, ensuring that generation checks do not fail on pre-existing code.
Change detection for go.mod and go.sum is improved using git diff --exit-code, and the script now uses temporary files for more reliable output verification.

Fixes #4894
Fixes #4895

[gemini-code-assist]

Code Review

This pull request updates the license URL in the .golangci.yaml file from http to https. I have no further feedback to provide as the change is straightforward and correct.