fix: etcd scheme on grpc resolver

[kevwan]

1. because resolver logic changed in grpc new versions
2. after idle, grpc close the builder and call Build method again

[codecov]

Codecov Report

Attention: Patch coverage is 61.11111% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 95.12%. Comparing base (8690859) to head (403cec0).
Report is 36 commits behind head on master.

❗ Current head 403cec0 differs from pull request most recent head 4c13f14. Consider uploading reports for the commit 4c13f14 to get more accurate results

Additional details and impacted files

Files	Coverage Δ
zrpc/resolver/internal/kubebuilder.go	16.36% <0.00%> (-4.40%)	⬇️
zrpc/resolver/internal/discovbuilder.go	51.51% <64.70%> (+13.05%)	⬆️

... and 253 files with indirect coverage changes