black: clean up noqa comments from most of the code

Many noqa's in the code are no longer necessary now that the column limit is 99
characters. Others can easily be eliminated, and still more can just be made more
specific if they do not have to do with line length.

The only E501's still in the code are in the tests for `spack.util.path` and the tests
for `spack style`.

bin/haspywin.py

@@ -8,7 +8,7 @@
 
 def getpywin():
     try:
-        import win32con  # noqa
+        import win32con  # noqa: F401
     except ImportError:
         subprocess.check_call(
             [sys.executable, "-m", "pip", "-q", "install", "--upgrade", "pip"])

bin/spack

@@ -82,7 +82,7 @@ except ImportError:
         raise
     try:
         os.remove(argparse_pyc)
-        import argparse  # noqa
+        import argparse  # noqa: F401
     except Exception:
         msg = ('The file\n\n\t{0}\n\nis corrupted and cannot be deleted by Spack. '
                'Either delete it manually or ask some administrator to '
@@ -91,7 +91,7 @@ except ImportError:
         sys.exit(1)
 
 
-import spack.main  # noqa
+import spack.main  # noqa: E402
 
 # Once we've set up the system path, run the spack main method
 if __name__ == "__main__":