librealsense2: cleanup patching

There is no need for the version conditional, as every distro uses the
same version (or newer in the future).

distros/ros2-overlay.nix

@@ -72,19 +72,15 @@ rosSelf: rosSuper: with rosSelf.lib; {
     cmakeFlags = cmakeFlags ++ [ "-DDOWNLOAD_TOML_LIB=OFF" ];
   });
 
+  # Get rid of nlohmann_json vendoring
   librealsense2 = rosSuper.librealsense2.overrideAttrs ({
-    buildInputs, postPatch ? "", version, ...
+    buildInputs ? [], postPatch ? "", ...
   }: {
-    buildInputs = buildInputs ++
-                  (if version >= "2.55.1" then
-                    [ self.nlohmann_json ]
-                   else []);
-    postPatch = postPatch +
-                (if version >= "2.55.1" then
-                  ''
-  substituteInPlace third-party/CMakeLists.txt --replace-fail 'include(CMake/external_json.cmake)' ""
-''
-                 else "");
+    buildInputs = buildInputs ++ [ self.nlohmann_json ];
+    postPatch = postPatch + ''
+      substituteInPlace third-party/CMakeLists.txt \
+        --replace-fail 'include(CMake/external_json.cmake)' ""
+    '';
   });
 
   popf = rosSuper.popf.overrideAttrs ({