chore(deps): update matrixdotorg/sygnal docker tag to v0.15.0

roles/custom/matrix-sygnal/defaults/main.yml

@@ -13,7 +13,7 @@ matrix_sygnal_hostname: ''
 matrix_sygnal_path_prefix: /
 
 # renovate: datasource=docker depName=matrixdotorg/sygnal
-matrix_sygnal_version: v0.14.3
+matrix_sygnal_version: v0.15.0
 
 matrix_sygnal_base_path: "{{ matrix_base_data_path }}/sygnal"
 matrix_sygnal_config_path: "{{ matrix_sygnal_base_path }}/config"