Omit build number for LenovoYogaC630 os dimension

Change-Id: I2816a6fca59adefd7dbceb42c9be2c6e9df5ea4a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/221345
Reviewed-by: Ben Wagner aka dogben <benjaminwagner@google.com>
Commit-Queue: Ben Wagner aka dogben <benjaminwagner@google.com>

infra/bots/gen_tasks.go

@@ -476,6 +476,10 @@ func defaultSwarmDimensions(parts map[string]string) []string {
 			// Upgrades result in a new image but not a new OS version.
 			d["image"] = "windows-server-2016-dc-v20190108"
 		}
+		if parts["model"] == "LenovoYogaC630" {
+			// This is currently a unique snowflake.
+			d["os"] = "Windows-10"
+		}
 	} else {
 		d["os"] = DEFAULT_OS_DEBIAN
 	}

infra/bots/tasks.json

@@ -76506,7 +76506,7 @@
       ],
       "dimensions": [
         "cpu:arm64-64-Snapdragon850",
-        "os:Windows-10-17763.503",
+        "os:Windows-10",
         "pool:Skia"
       ],
       "env_prefixes": {
@@ -76617,7 +76617,7 @@
       ],
       "dimensions": [
         "gpu:Adreno630",
-        "os:Windows-10-17763.503",
+        "os:Windows-10",
         "pool:Skia"
       ],
       "env_prefixes": {