Sync shell script static analysis task from template

- Use standardized task name
- Add support for arbitrary file extensions and path configurations (which is not possible with the previous globstar
  approach)

Author: per1234

.github/workflows/lint-shell.yml

@@ -25,4 +25,4 @@ jobs:
           version: 3.x
 
       - name: Lint shell scripts
-        run: task shell:lint
+        run: task shell:check

Taskfile.yml

@@ -266,17 +266,33 @@ tasks:
     cmds:
       - npx {{ .PRETTIER }} --write "**/*.md"
 
-  shell:lint:
-    desc: Lint shell scripts
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-shell-task/Taskfile.yml
+  shell:check:
+    desc: Check for problems with shell scripts
     cmds:
       - |
         if ! which shellcheck &>/dev/null; then
           echo "shellcheck not installed or not in PATH. Please install: https://github.com/koalaman/shellcheck#installing"
           exit 1
         fi
       - |
-        shopt -s globstar # Needed to check all scripts recursively.
-        shellcheck ./**/*.sh
+        # There is something odd about shellcheck that causes the task to always exit on the first fail, despite any
+        # measures that would prevent this with any other command. So it's necessary to call shellcheck only once with
+        # the list of script paths as an argument. This could lead to exceeding the maximum command length on Windows if
+        # the repository contained a large number of scripts, but it's unlikely to happen in reality.
+        shellcheck \
+          --format={{default "tty" .SHELLCHECK_FORMAT}} \
+          $(
+            # The odd method for escaping . in the regex is required for windows compatibility because mvdan.cc/sh gives
+            # \ characters special treatment on Windows in an attempt to support them as path separators.
+            find . \
+              -path ".git" -prune -or \
+              \( \
+                -regextype posix-extended \
+                -regex '.*[.](bash|sh)' -and \
+                -type f \
+              \)
+          )
 
   shell:check-formatting:
     desc: Format shell scripts