Add missing relational operator

Co-authored-by: Oscar Gustafsson <oscar.gustafsson@gmail.com>

Author: devRD

lib/matplotlib/_mathtext.py

@@ -1748,7 +1748,7 @@ class _MathStyle(enum.Enum):
       \in         \ni         \propto  \vdash
       \dashv      \dots       \doteqdot
       \leqq       \geqq       \lneqq   \gneqq
-      \lessgtr \leqslant \eqgtr \eqless
+      \lessgtr \leqslant \geqslant \eqgtr \eqless
       \eqslantless \eqslantgtr \lesseqgtr
       \backsim \backsimeq \lesssim \gtrsim
       \precsim \precnsim \gnsim \lnsim