Update pxt-core to 11.4.27 (#6320)

Author: thsparks

package.json

@@ -46,7 +46,7 @@
     },
     "dependencies": {
         "pxt-common-packages": "12.3.30",
-        "pxt-core": "11.4.25"
+        "pxt-core": "11.4.27"
     },
     "overrides": {
         "@blockly/field-colour": {