Remove cutout for missing font file in PdfFile._embedTeXFont.

If fontfile is None, an error would already have been raised earlier in
dviFontName (which explicitly checks for this case).

(The cutout in _embedTeXFont was introduced first, in ed0066f (2009),
but support for that case appears to have been broken a bit later and
the check in dviFontName was then introduced in 4fcc0e7 (2016) where it
simply improved the clarity of the exception ultimately raised.)

Author: anntzer

lib/matplotlib/backends/backend_pdf.py

@@ -1021,18 +1021,6 @@ def _embedTeXFont(self, fontinfo):
                     0, *map(Name, dviread._parse_enc(fontinfo.encodingfile))],
             }
 
-        # If no file is specified, stop short
-        if fontinfo.fontfile is None:
-            _log.warning(
-                "Because of TeX configuration (pdftex.map, see updmap option "
-                "pdftexDownloadBase14) the font %s is not embedded. This is "
-                "deprecated as of PDF 1.5 and it may cause the consumer "
-                "application to show something that was not intended.",
-                fontinfo.basefont)
-            fontdict['BaseFont'] = Name(fontinfo.basefont)
-            self.writeObject(fontdictObject, fontdict)
-            return fontdictObject
-
         # We have a font file to embed - read it in and apply any effects
         t1font = _type1font.Type1Font(fontinfo.fontfile)
         if fontinfo.effects: