fix incompatible issue when using python3 script in 7.7 (#12436)

* fix incompatible method used for python script in 7.7

* Update GeneratePostPublishReport.py

scripts/GeneratePostPublishReport.py

@@ -33,7 +33,7 @@ def checkArchetypeMetaData(archetypeMetadataUrl, version):
 	if archetype_metadata_request.status_code != 200:
 		return createTableRow(traffic_light.format(color="black"), "Check archetype metadata: <a href='{url}'>unable to retrieve metadata from {url}</a>".format(url=archetypeMetadataUrl))
 	else:
-		if "version=\"{version}\"".format(version=version) in archetype_metadata_request.content:
+		if "version=\"{version}\"".format(version=version) in archetype_metadata_request.text:
 			return createTableRow(traffic_light.format(color="green"), "Check archetype metadata: <a href='{url}'>metadata is correct for {url}</a>".format(url=archetypeMetadataUrl))
 		else:
 			return createTableRow(traffic_light.format(color="red"), "Check archetype metadata: <a href='{url}'>metadata seems to be incorrect for {url}</a>".format(url=archetypeMetadataUrl))
@@ -66,5 +66,5 @@ content += createTableRow("", "<a href=\"https://github.com/vaadin/framework/rel
 
 content += "</table></body></html>"
 
-with open("result/report.html", "wb") as f:
+with open("result/report.html", "w") as f:
 	f.write(content)