Merge pull request #62709 from tshortli/swift-api-dump-utf8-5.8

[5.8] Utils: Decode subprocess output as UTF-8 in `swift-api-dump.py`.

Author: tshortli

utils/swift-api-dump.py

@@ -127,6 +127,7 @@ def run_command(args):
     proc = subprocess.Popen(
         args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     out, err = proc.communicate()
+    out = out.decode('UTF8')
     exitcode = proc.returncode
     return (exitcode, out, err)