[DO-971] ffmpeg recipe with requirements (!9)

Co-authored-by: aleksandr.vodyanov <aleksandr.vodyanov@avroid.tech>
Reviewed-on: https://git.avroid.tech/Conan/conan_build/pulls/9

recipes/libsndfile/all/patches/1.0.31-0001-fix-msvc-runtime-logic.patch

@@ -0,0 +1,11 @@
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -8,7 +8,7 @@ if (POLICY CMP0091)
+ 		return ()
+ 	endif ()
+ 
+-	if (DEFINED CMAKE_MSVC_RUNTIME_LIBRARY)
++	if (1)
+ 		cmake_policy (SET CMP0091 NEW)
+ 	else ()
+ 		cmake_policy (SET CMP0091 OLD)