Remove CRLF, enforce with workflow (#26401)

* Check for CRLF in actions workflow

Make emisse weep

* Copy paste bottom text

* I would like to thank StackOverflow for this spite PR.

* Mention file name in message because the workflow tab doesn't display it.

* dos2unix everything

Tools/check_crlf.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+
+import subprocess
+from typing import Iterable
+
+def main() -> int:
+    any_failed = False
+    for file_name in get_text_files():
+        if is_file_crlf(file_name):
+            print(f"::error file={file_name},title=File contains CRLF line endings::The file '{file_name}' was committed with CRLF new lines. Please make sure your git client is configured correctly and you are not uploading files directly to GitHub via the web interface.")
+            any_failed = True
+
+    return 1 if any_failed else 0
+
+
+def get_text_files() -> Iterable[str]:
+    # https://stackoverflow.com/a/24350112/4678631
+    process = subprocess.run(
+        ["git", "grep", "--cached", "-Il", ""],
+        check=True,
+        encoding="utf-8",
+        stdout=subprocess.PIPE)
+
+    for x in process.stdout.splitlines():
+        yield x.strip()
+
+def is_file_crlf(path: str) -> bool:
+    # https://stackoverflow.com/a/29697732/4678631
+    with open(path, "rb") as f:
+        for line in f:
+            if line.endswith(b"\r\n"):
+                return True
+
+    return False
+
+exit(main())