vendor: update buildkit to v0.8

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/google.golang.org/grpc/dialoptions.go

@@ -72,6 +72,7 @@ type dialOptions struct {
 	// we need to be able to configure this in tests.
 	resolveNowBackoff func(int) time.Duration
 	resolvers         []resolver.Builder
+	withProxy         bool
 }
 
 // DialOption configures how we set up the connection.
@@ -307,6 +308,16 @@ func WithInsecure() DialOption {
 	})
 }
 
+// WithNoProxy returns a DialOption which disables the use of proxies for this
+// ClientConn. This is ignored if WithDialer or WithContextDialer are used.
+//
+// This API is EXPERIMENTAL.
+func WithNoProxy() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.withProxy = false
+	})
+}
+
 // WithTransportCredentials returns a DialOption which configures a connection
 // level security credentials (e.g., TLS/SSL). This should not be used together
 // with WithCredentialsBundle.
@@ -557,6 +568,7 @@ func defaultDialOptions() dialOptions {
 			ReadBufferSize:  defaultReadBufSize,
 		},
 		resolveNowBackoff: internalbackoff.DefaultExponential.Backoff,
+		withProxy:         true,
 	}
 }