deps/mautrix: upgrade to 0.20.5

Signed-off-by: Sumner Evans <[email protected]>

requirements.txt

@@ -3,7 +3,7 @@ asyncpg>=0.20,<0.28
 beautifulsoup4>=4,<5
 commonmark>=0.8,<0.10
 dataclasses-json>=0.6.3,<0.7
-mautrix>=0.20.1,<0.21
+mautrix>=0.20.5,<0.21
 pycryptodome>=3,<4
 python-magic>=0.4,<0.5
 ruamel.yaml>=0.15.94,<0.19