Remove unnecessary fortran dependency

This results in an error from `which` during the cygport compile stage,
but I think that's a fair trade-off for not needing to install
gcc-fortran when it's otherwise unused.

taskwarrior.cygport

@@ -10,7 +10,7 @@ GIT_URI=https://github.com/GothenburgBitFactory/taskwarrior
 GIT_TAG="v$PV"
 LICENSE=MIT
 
-BUILD_REQUIRES='cmake gcc-fortran ninja libuuid-devel libgnutls-devel python3'
+BUILD_REQUIRES='cmake ninja libuuid-devel libgnutls-devel python3'
 
 inherit cmake
 inherit git