Remove unnecessary coding: utf-8 heading from Python scripts

Python 3 uses UTF-8 for source files by default. This removes the
unnecessary `coding: utf-8` declaration comment from all files.

Scripts/AuditStringH.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/ProtoWrappers.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/precommit.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/reverse_integration_check.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 # When we make a hotfix, we need to reverse integrate our hotfix back into
 # master. After committing to master, this script audits that all tags have been

Scripts/sds_codegen/sds_common.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import subprocess

Scripts/sds_codegen/sds_generate.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/sds_codegen/sds_parse_objc.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/sds_codegen/sds_parse_swift_bridging.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

Scripts/sds_codegen/sds_swap_imports.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys

SignalServiceKit/Utilities/extract_analytics_event_names.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import sys