pyupgrade: Replace Text with str.

We uses `pyupgrade --py3-plus` to automatically replace all occurence
of `Text`. But manual fix is required to remove the unused imports. Note
that with this configuration pyupgrade also convert string literals to
.format(...) style, which is manually not included in the commit as well.

zulip/integrations/hg/zulip_changegroup.py

@@ -6,7 +6,6 @@
 # `hg push`). See https://zulip.com/integrations for installation instructions.
 
 import sys
-from typing import Text
 
 from mercurial import repository as repo
 from mercurial import ui
@@ -17,8 +16,8 @@ VERSION = "0.9"
 
 
 def format_summary_line(
-    web_url: str, user: str, base: int, tip: int, branch: str, node: Text
-) -> Text:
+    web_url: str, user: str, base: int, tip: int, branch: str, node: str
+) -> str:
     """
     Format the first line of the message, which contains summary
     information about the changeset and links to the changelog if a
@@ -71,7 +70,7 @@ def format_commit_lines(web_url: str, repo: repo, base: int, tip: int) -> str:
 
 
 def send_zulip(
-    email: str, api_key: str, site: str, stream: str, subject: str, content: Text
+    email: str, api_key: str, site: str, stream: str, subject: str, content: str
 ) -> None:
     """
     Send a message to Zulip using the provided credentials, which should be for
@@ -100,7 +99,7 @@ def get_config(ui: ui, item: str) -> str:
         sys.exit(1)
 
 
-def hook(ui: ui, repo: repo, **kwargs: Text) -> None:
+def hook(ui: ui, repo: repo, **kwargs: str) -> None:
     """
     Invoked by configuring a [hook] entry in .hg/hgrc.
     """