deps: update vendor dependencies for S3-compatible storage

Updates AWS SDK and removes Blazer B2 dependency in favor of unified
S3-compatible approach. Includes configuration examples and documentation.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/github.com/aws/aws-sdk-go/service/sts/customizations.go

@@ -0,0 +1,11 @@
+package sts
+
+import "github.com/aws/aws-sdk-go/aws/request"
+
+func init() {
+	initRequest = customizeRequest
+}
+
+func customizeRequest(r *request.Request) {
+	r.RetryErrorCodes = append(r.RetryErrorCodes, ErrCodeIDPCommunicationErrorException)
+}