Pin the spelling action version, to match what's enabled in project settings

This matches https://github.com/Arduino-CI/arduino_ci/settings/actions

Author: ianfixes

.github/workflows/spelling.yaml

@@ -21,6 +21,6 @@ jobs:
           fetch-depth: 0
 
       - name: Check Spelling
-        uses: codespell-project/actions-codespell@master
+        uses: codespell-project/actions-codespell@v1.0
         with:
           check_filenames: true

exe/arduino_ci.rb

@@ -100,7 +100,7 @@ def terminate(final = nil)
 end
 
 # make a nice status line for an action and react to the action
-# TODO / note to self: inform_multline is tougher to write
+# TODO / note to self: inform_multiline is tougher to write
 #   without altering the signature because it only leaves space
 #   for the checkmark _after_ the multiline, it doesn't know how
 #   to make that conditionally the body
@@ -121,7 +121,7 @@ def perform_action(message, multiline, mark_fn, on_fail_msg, tally_on_fail, abor
   $stdout.flush
   result = yield
   mark = mark_fn.nil? ? "" : mark_fn.call(result)
-  # if multline, put checkmark at full width
+  # if multiline, put checkmark at full width
   print endline if multiline
   puts mark.to_s.rjust(WIDTH - line.length, " ")
   unless result