gnunet: update to version 0.25.1

GNUnet 0.25 dropped the autotools based build system and now requires
being built with Meson. As expected there are some cross-compiling
related issues which have been fixed using downstream patches by now.

v0.25.1:
  - transport: hotfix incorrect communicator key derivations
  - tests: make failing tests work again
  - util: Change to assigned HPKE codepoint for DHKEM+Elligator. See https://www.iana.org/assignments/hpke/
  - fs: service failed to start because of PILS addition

v0.25.0:
  - util: Removed authkem from HPKE implementation as it is going to be removed from the RFC9180bis spec and is unused in GNUnet anyway.
  - core: New AKE implementation.
  - pils: New service.
  - gns: Various improvements to performance and DNS migration tooling.
  - build: Retired autotools.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

net/gnunet/patches/0007-namecache-install-sql-files.patch

@@ -0,0 +1,31 @@
+From 94aa64ed0363e8c62f126cfe42843468cc775132 Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Fri, 10 Oct 2025 01:33:41 +0100
+Subject: [PATCH 7/8] namecache: install sql files
+
+---
+ src/plugin/namecache/meson.build | 16 ++++++++++++++++
+ 1 file changed, 16 insertions(+)
+
+--- a/src/plugin/namecache/meson.build
++++ b/src/plugin/namecache/meson.build
+@@ -1,3 +1,19 @@
++configure_file(
++    input: 'namecache-0001.sql',
++    output: 'namecache-0001.sql',
++    configuration: cdata,
++    install: true,
++    install_dir: get_option('datadir') / 'gnunet' / 'sql',
++)
++
++configure_file(
++    input: 'namecache-drop.sql',
++    output: 'namecache-drop.sql',
++    configuration: cdata,
++    install: true,
++    install_dir: get_option('datadir') / 'gnunet' / 'sql',
++)
++
+ shared_module(
+     'gnunet_plugin_namecache_sqlite',
+     ['plugin_namecache_sqlite.c'],