libcamera: move to pkgs/by-name

The CI check complains about a new attribute introduced that's not using
the by-name pattern, even though it's using the same .nix file.

It seems using callPackage ../by-name/… from toplevel for the
alternative toplevel attribute seems to be others do this, so using the
same pattern here.

pkgs/top-level/all-packages.nix

@@ -22463,9 +22463,7 @@ with pkgs;
 
   libcacard = callPackage ../development/libraries/libcacard { };
 
-  libcamera = callPackage ../development/libraries/libcamera { };
-
-  libcamera-qcam = callPackage ../development/libraries/libcamera { withQcam = true; };
+  libcamera-qcam = callPackage ../by-name/li/libcamera/package.nix { withQcam = true; };
 
   libcanberra = callPackage ../development/libraries/libcanberra {
     inherit (darwin.apple_sdk.frameworks) Carbon CoreServices AppKit;