Use official GitHub Actions action for spell checking

The `arduino/actions/libraries/spell-check` GitHub Actions action is now deprecated in favor of the official action from
codespell.

The 2.0.0 release of codespell added support for a .codespellrc configuration file. Use of this file to configure
codespell allows the spell check to be run locally with the identical configuration to that used by the CI system.

Author: per1234

.codespellrc

@@ -0,0 +1,7 @@
+# See: https://github.com/codespell-project/codespell#using-a-config-file
+[codespell]
+# In the event of a false positive, add the problematic word, in all lowercase, to a comma-separated list here:
+ignore-words-list = alocation,wan
+check-filenames =
+check-hidden =
+skip = ./.git,./extras/test/external,./src/cbor/lib/tinycbor

.github/workflows/spell-check.yml

@@ -13,7 +13,4 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Spell check
-        uses: arduino/actions/libraries/spell-check@master
-        with:
-          ignore-words-list: extras/codespell-ignore-words-list.txt
-          skip-paths: ./extras/test/external,./src/cbor/lib/tinycbor
+        uses: codespell-project/actions-codespell@master