libcmatrix: Update to version supporting authenticated media

Needed to e.g. unbreak image downloads from matrix.org

See

  https://matrix.org/blog/2024/06/20/matrix-v1.11-release/

and

  matrix-org/matrix-spec-proposals#3916

for details.

Part-of: <https://gitlab.gnome.org/World/Chatty/-/merge_requests/1444>

Author: agx

subprojects/libcmatrix.wrap

@@ -1,4 +1,5 @@
 [wrap-git]
 directory=libcmatrix
-url=https://source.puri.sm/Librem5/libcmatrix
-revision=v0.0.2
+url=https://source.puri.sm/Librem5/libcmatrix.git
+revision=7c4a4b44e0c0179d382071d6da70a6af8459031e
+depth=1