Pretest "tlmgr update" failed updating language.dat

[Karl Berry]

        Cannot open
        /usr/local/texlive/2025/texmf-var/tex/generic/config/language.dat
        for writing: No such file or directory at
        /usr/local/texlive/2025/tlpkg/TeXLive/TLUtils.pm line 3669.

    I guess TLUtils.pm should probably do the equivalent of
        mkdir -p $TEXMFSYSVAR/tex/generic/config/

I guess, although it seems strange that it apparently didn't fail for
anyone else. Anyway, I made the change (r74083) since it "should" be
harmless.  Famous last words.  We'll see.  --thanks, karl.

--- Master/tlpkg/TeXLive/TLUtils.pm	(revision 74082)
+++ Master/tlpkg/TeXLive/TLUtils.pm	(working copy)
@@ -3666,6 +3666,9 @@
     tlwarn("Updating $dest, backup copy in $dest.backup\n");
     copy("-f", $dest, "$dest.backup");
   }
+  # ensure destination directory exists.
+  my $destdir = dirname ($dest);
+  -d $destdir || mkdirhier $destdir; # if fails, the next open will die.
   open(OUTFILE,">$dest")
     or die("Cannot open $dest for writing: $!");