Remove Python 2 support

Python 2 is long dead and devlib does not support it anymore, so cleanup
old Python 2-only code.

wa/workloads/jankbench/__init__.py

@@ -223,8 +223,7 @@ class JankbenchRunMonitor(threading.Thread):
                 ready, _, _ = select.select([proc.stdout, proc.stderr], [], [], 2)
                 if ready:
                     line = ready[0].readline()
-                    if sys.version_info[0] == 3:
-                        line = line.decode(sys.stdout.encoding, 'replace')
+                    line = line.decode(sys.stdout.encoding, 'replace')
                     if self.regex.search(line):
                         self.run_ended.set()
         proc.terminate()

wa/workloads/meabo/__init__.py

@@ -256,10 +256,7 @@ class Meabo(Workload):
 
         outfile = os.path.join(context.output_directory, 'meabo-output.txt')
         with open(outfile, 'wb') as wfh:
-            if sys.version_info[0] == 3:
-                wfh.write(self.output.encode('utf-8'))
-            else:
-                wfh.write(self.output)
+            wfh.write(self.output.encode('utf-8'))
         context.add_artifact('meabo-output', outfile, kind='raw')
 
         cur_phase = 0

wa/workloads/pcmark/__init__.py

@@ -89,8 +89,7 @@ class PcMark(ApkUiautoWorkload):
     def update_output(self, context):
         expected_results = len(self.regex_matches[self.major_version])
         zf = zipfile.ZipFile(os.path.join(context.output_directory, self.result_file), 'r').read('Result.xml')
-        if sys.version_info[0] == 3:
-            zf = zf.decode(sys.stdout.encoding)
+        zf = zf.decode(sys.stdout.encoding)
         for line in zf.split('\n'):
             for regex in self.regex_matches[self.major_version]:
                 match = regex.search(line)