all: Fix various user-facing and non-user-facing typos (#8509)

Found via `codespell -q 3 -S lang,./gui/default/vendor -L benchs,bu,inflight,ro`

lib/fs/basicfs_fileinfo_windows.go

@@ -37,7 +37,7 @@ func (e basicFileInfo) Mode() FileMode {
 		// NTFS deduped files. Remove the symlink bit.
 		m &^= os.ModeSymlink
 	}
-	// Set executable bits on files with executable extenions (.exe, .bat, etc).
+	// Set executable bits on files with executable extensions (.exe, .bat, etc).
 	if isWindowsExecutable(e.Name()) {
 		m |= 0111
 	}