Breaking Changes

GCE

• Refactored authentication to use Application Default Credentials (ADC) instead of JSON keyfile
• NewGCE(keyfile, zone string) changed to NewGCE(zone string)
• GCE_KEY environment variable is no longer used
• New required environment variables: GOOGLE_PROJECT and GOOGLE_SERVICE_ACCOUNT_EMAIL
• Optional: GOOGLE_APPLICATION_CREDENTIALS for service account JSON (if not using gcloud auth application-default login)

Azure

• Removed unused authFile parameter from NewAzure() function
• NewAzure(authFile string) changed to NewAzure()
• AZURE_AUTH_LOCATION environment variable is no longer used (it was never actually used in the implementation)

Other Changes

• Updated golangci-lint config to v2 format