package/doxygen: bump version to 1.15.0

Changelog of this host-only package:
https://www.doxygen.nl/manual/changelog.html

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/doxygen/doxygen.hash

@@ -1,3 +1,3 @@
 # Computed locally
-sha256  18173d9edc46d2d116c1f92a95d683ec76b6b4b45b817ac4f245bb1073d00656  doxygen-1.8.18.src.tar.gz
+sha256  a8cafe605867ad475aaf288a3852783076e1df83aabf16488bbfa958062e7440  doxygen-1.15.0.src.tar.gz
 sha256  8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643  LICENSE

package/doxygen/doxygen.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-DOXYGEN_VERSION = 1.8.18
+DOXYGEN_VERSION = 1.15.0
 DOXYGEN_SOURCE = doxygen-$(DOXYGEN_VERSION).src.tar.gz
 DOXYGEN_SITE = https://sourceforge.net/projects/doxygen/files/rel-$(DOXYGEN_VERSION)
 DOXYGEN_LICENSE = GPL-2.0