codespell.yml: Make CI reject spelling errors using codespell

.github/workflows/codespell.yml

@@ -0,0 +1,51 @@
+#                          __  __            _
+#                       ___\ \/ /_ __   __ _| |_
+#                      / _ \\  /| '_ \ / _` | __|
+#                     |  __//  \| |_) | (_| | |_
+#                      \___/_/\_\ .__/ \__,_|\__|
+#                               |_| XML parser
+#
+# Copyright (c) 2023      Sebastian Pipping <sebastian@pipping.org>
+# Licensed under the MIT license:
+#
+# Permission is  hereby granted,  free of charge,  to any  person obtaining
+# a  copy  of  this  software   and  associated  documentation  files  (the
+# "Software"),  to  deal in  the  Software  without restriction,  including
+# without  limitation the  rights  to use,  copy,  modify, merge,  publish,
+# distribute, sublicense, and/or sell copies of the Software, and to permit
+# persons  to whom  the Software  is  furnished to  do so,  subject to  the
+# following conditions:
+#
+# The above copyright  notice and this permission notice  shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE  SOFTWARE  IS  PROVIDED  "AS  IS",  WITHOUT  WARRANTY  OF  ANY  KIND,
+# EXPRESS  OR IMPLIED,  INCLUDING  BUT  NOT LIMITED  TO  THE WARRANTIES  OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+# NO EVENT SHALL THE AUTHORS OR  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+# DAMAGES OR  OTHER LIABILITY, WHETHER  IN AN  ACTION OF CONTRACT,  TORT OR
+# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+# USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+name: Enforce codespell-clean spelling
+
+on:
+  pull_request:
+  push:
+  schedule:
+    - cron: '0 2 * * 5'  # Every Friday at 2am
+
+permissions:
+  contents: read
+
+jobs:
+  checks:
+    name: Enforce codespell-clean spelling
+    runs-on: ubuntu-22.04
+    steps:
+    - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744  # v3.6.0
+    - uses: codespell-project/actions-codespell@94259cd8be02ad2903ba34a22d9c13de21a74461  # v2.0
+      with:
+        path: expat/
+        # This is from "[n]otation" in xmlwf help output
+        ignore_words_list: otation