mypy: zulip: Fix errors in integrations/zephyr/process_ccache.

tools/run-mypy

@@ -20,7 +20,6 @@ sys.path.append(os.path.dirname(TOOLS_DIR))
 
 exclude = """
 zulip/integrations/perforce/git_p4.py
-zulip/integrations/zephyr/process_ccache
 zulip/tests/__init__.py
 zulip/tests/test_default_arguments.py
 

zulip/integrations/zephyr/process_ccache

@@ -10,7 +10,7 @@ ccache_data_encoded = sys.argv[3]
 
 # Update the Kerberos ticket cache file
 program_name = "zmirror-%s" % (short_user,)
-with open("/home/zulip/ccache/%s" % (program_name,), "w") as f:
+with open("/home/zulip/ccache/%s" % (program_name,), "wb") as f:
     f.write(base64.b64decode(ccache_data_encoded))
 
 # Setup API key