Revert grpc bump (#1003)

grpc 1.73.0 seems to degrade memory usage (to be confirmed)

Author: jotak

go.mod

@@ -42,7 +42,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.36.0
 	go.opentelemetry.io/otel/sdk/metric v1.36.0
 	golang.org/x/net v0.41.0
-	google.golang.org/grpc v1.73.0
+	google.golang.org/grpc v1.72.2
 	google.golang.org/protobuf v1.36.6
 	gopkg.in/yaml.v2 v2.4.0
 	k8s.io/api v0.32.3

go.sum

@@ -546,8 +546,8 @@ google.golang.org/genproto/googleapis/api v0.0.0-20250603155806-513f23925822 h1:
 google.golang.org/genproto/googleapis/api v0.0.0-20250603155806-513f23925822/go.mod h1:h3c4v36UTKzUiuaOKQ6gr3S+0hovBtUrXzTG/i3+XEc=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250603155806-513f23925822 h1:fc6jSaCT0vBduLYZHYrBBNY4dsWuvgyff9noRNDdBeE=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250603155806-513f23925822/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
-google.golang.org/grpc v1.73.0 h1:VIWSmpI2MegBtTuFt5/JWy2oXxtjJ/e89Z70ImfD2ok=
-google.golang.org/grpc v1.73.0/go.mod h1:50sbHOUqWoCQGI8V2HQLJM0B+LMlIUjNSZmow7EVBQc=
+google.golang.org/grpc v1.72.2 h1:TdbGzwb82ty4OusHWepvFWGLgIbNo1/SUynEN0ssqv8=
+google.golang.org/grpc v1.72.2/go.mod h1:wH5Aktxcg25y1I3w7H69nHfXdOG3UiadoBtjh3izSDM=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=