fonts/jetbrains-mono: Fix the license marker

Index: Makefile
===================================================================
RCS file: /cvs/ports/fonts/jetbrains-mono/Makefile,v
retrieving revision 1.4
diff -u -p -r1.4 Makefile
--- Makefile 11 Mar 2022 19:00:21 -0000 1.4
+++ Makefile 12 Mar 2023 20:34:53 -0000
@@ -8,7 +8,7 @@ CATEGORIES = fonts x11

HOMEPAGE = https://www.jetbrains.com/lp/mono/

-# Apache 2.0
+# SIL OFL 1.1
PERMIT_PACKAGE = Yes

MASTER_SITES = https://download.jetbrains.com/fonts/