Typo fixes in .flake8 comments (#10399)

.flake8_packages

@@ -7,16 +7,18 @@
 # wildcard import and dependencies can set globals for their
 # dependents. So we add exceptions for checks related to undefined names.
 #
-# Note that we also add *per-line* exemptions for certain patters in the
+# Note that we also add *per-line* exemptions for certain patterns in the
 # `spack flake8` command.  This is where F403 for `from spack import *`
 # is added (beause we *only* allow that wildcard).
 #
 # See .flake8 for regular exceptions.
 #
-# Redefinition exceptions:
+# F4: Import
 # - F405: `name` may be undefined, or undefined from star imports: `module`
-# - F821: undefined name `name` (needed for cmake, configure, etc.)
+#
+# F8: Name
+# - F821: undefined name `name`
 #
 [flake8]
-ignore = E129,E221,E241,E272,E731,F999,F405,F821,W503,W504
+ignore = E129,E221,E241,E272,E731,W503,W504,F405,F821,F999
 max-line-length = 79