Meta: Rewrite the check-newlines-at-eof script in python

The bash version takes around 15 seconds to run; that is way too slow.
This python3 version should take less than one second to run. :^)

Also, the script will now also check .py files and .txt CMake files.

Meta/check-newlines-at-eof.py

@@ -0,0 +1,62 @@
+#!/bin/python3
+
+import os
+import subprocess
+import sys
+
+os.chdir(os.path.dirname(__file__) + "/..")
+
+files = subprocess.run(
+    [
+        "git", "ls-files", "--",
+        "*.cpp",
+        "*.h",
+        "*.gml",
+        "*.html",
+        "*.js",
+        "*.css",
+        "*.sh",
+        "*.py",
+        "CMake*.txt",
+        "**/CMake*.txt",
+        ":!:Base",
+        ":!:Kernel/FileSystem/ext2_fs.h",
+        ":!:Libraries/LibC/getopt.cpp",
+        ":!:Libraries/LibCore/puff.h",
+        ":!:Libraries/LibCore/puff.cpp",
+        ":!:Libraries/LibELF/exec_elf.h"
+    ],
+    capture_output=True
+).stdout.decode().strip('\n').split('\n')
+
+no_newline_at_eof_errors = []
+blank_lines_at_eof_errors = []
+
+did_fail = False
+for filename in files:
+    with open(filename, "r") as f:
+        f.seek(0, os.SEEK_END)
+
+        f.seek(f.tell() - 1, os.SEEK_SET)
+        if f.read(1) != '\n':
+            did_fail = True
+            no_newline_at_eof_errors.append(filename)
+            continue
+
+        while True:
+            f.seek(f.tell() - 2, os.SEEK_SET)
+            char = f.read(1)
+            if not char.isspace():
+                break
+            if char == '\n':
+                did_fail = True
+                blank_lines_at_eof_errors.append(filename)
+                break
+
+if no_newline_at_eof_errors:
+    print("Files with no newline at the end:", " ".join(no_newline_at_eof_errors))
+if blank_lines_at_eof_errors:
+    print("Files that have blank lines at the end:", " ".join(blank_lines_at_eof_errors))
+
+if did_fail:
+    sys.exit(1)