Fix compilation with emscripten 4.0.9

Patch MbedTLS to fix a legit compilation error
Also bump mbedtls to 3.6.3.1

Signed-off-by: Paul Guyot <pguyot@kallisys.net>

Author: pguyot

CMakeModules/FetchMbedTLS.cmake

@@ -22,8 +22,9 @@ include(FetchContent)
 
 FetchContent_Declare(
   mbedtls
+  PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/mbedtls.patch"
   GIT_REPOSITORY http://github.com/mbed-TLS/mbedtls.git
-  GIT_TAG        v3.6.2
+  GIT_TAG        v3.6.3.1
   GIT_SHALLOW    1
 )
 

CMakeModules/mbedtls.patch

@@ -0,0 +1,15 @@
+# Copyright 2025 Paul Guyot <pguyot@kallisys.net>
+# SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+diff --git a/framework/tests/src/psa_exercise_key.c b/framework/tests/src/psa_exercise_key.c
+index b92c1f75..eaa35527 100644
+--- a/framework/tests/src/psa_exercise_key.c
++++ b/framework/tests/src/psa_exercise_key.c
+@@ -184,7 +184,7 @@ static int exercise_cipher_key(mbedtls_svc_key_id_t key,
+     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+     psa_key_type_t key_type;
+     const unsigned char plaintext[16] = "Hello, world...";
+-    unsigned char ciphertext[32] = "(wabblewebblewibblewobblewubble)";
++    unsigned char ciphertext[33] = "(wabblewebblewibblewobblewubble)";
+     size_t ciphertext_length = sizeof(ciphertext);
+     unsigned char decrypted[sizeof(ciphertext)];
+     size_t part_length;