Allow building with filepath-1.5.*. Refs #39.

This allows `copilot-bluespec` to build with the version of `filepath` bundled
with GHC 9.10 or later.

Author: RyanGlScott

copilot-bluespec.cabal

@@ -41,7 +41,7 @@ library
   ghc-options             : -Wall
   build-depends           : base              >= 4.9    && < 5
                           , directory         >= 1.3    && < 1.4
-                          , filepath          >= 1.4    && < 1.5
+                          , filepath          >= 1.4    && < 1.6
                           , pretty            >= 1.1.2  && < 1.2
 
                           , copilot-core      >= 4.3    && < 4.4