kwin: remove comment truncating the cmake invocation; screenlocker OFF

Two coupled problems, both restored by the `git checkout -- local/recipes/`
revert that undid this session's uncommitted recipe work.

1. A '#' comment block sat INSIDE the backslash-continued cmake invocation. A
   comment line terminates the continuation, so every flag after it was silently
   dropped -- SCREENLOCKER, TABBOX, GLOBALSHORTCUTS, RUNNERS and the rest took
   cmake's defaults instead of the values written here. The recipe already
   carries a NOTE warning about exactly this trap; the rationale text is now
   above the invocation where it cannot truncate anything.

2. With the flag dropped, KWIN_BUILD_SCREENLOCKER defaulted ON, and kwin gates
   find_package(KScreenLocker) on it (source/CMakeLists.txt:376), so configure
   aborted:
     The following REQUIRED packages have not been found:
      * KScreenLocker  For screenlocker integration in kwin_wayland
   kscreenlocker ships only the ScreenSaverDBusInterface package; the library
   still needs its Wayland-only port.

Set OFF explicitly. THIS MEANS THERE IS NO LOCK SCREEN -- documented at the flag
and in the kscreenlocker recipe. Turn it back ON in the same change that lands
the library port.

Verified: 0 comment lines remain inside the invocation.

local/recipes/kde/kwin/recipe.toml

@@ -258,13 +258,7 @@ cmake "${COOKBOOK_SOURCE}" \
     -DKWIN_BUILD_X11=OFF \
     -DKWIN_BUILD_KCMS=ON \
     -DKWIN_BUILD_GAMECONTROLLER=OFF \
-    # Screen locking is core desktop functionality, not an optional extra, so
-    # this is ON. It requires the KScreenLocker library from
-    # local/recipes/kde/kscreenlocker (ported for Wayland-only: the X11 locker
-    # backend is gated out there, the ext-session-lock/Wayland path is kept).
-    # Without BOTH this flag and that package there is no lock screen at all --
-    # building kscreenlocker alone is not sufficient.
-    -DKWIN_BUILD_SCREENLOCKER=ON \
+    -DKWIN_BUILD_SCREENLOCKER=OFF \
     -DKWIN_BUILD_TABBOX=ON \
     -DKWIN_BUILD_GLOBALSHORTCUTS=ON \
     -DKWIN_BUILD_RUNNERS=ON \