fluffychat: fix sqlite3 library missing

There were errors about libsqlite3.so missing, which I fixed by adding it to runtime dependencies

pkgs/development/compilers/dart/package-source-builders/default.nix

···
   matrix = callPackage ./matrix { };
   media_kit_libs_linux = callPackage ./media_kit_libs_linux { };
   olm = callPackage ./olm { };
+  sqlite3 = callPackage ./sqlite3 { };
   system_tray = callPackage ./system-tray { };
 }

pkgs/development/compilers/dart/package-source-builders/sqlite3/default.nix

···
+{ stdenv
+, lib
+, writeScript
+, sqlite
+}:
+
+{ version, src, ... }:
+
+stdenv.mkDerivation rec {
+  pname = "sqlite3";
+  inherit version src;
+  inherit (src) passthru;
+
+  setupHook = writeScript "${pname}-setup-hook" ''
+    sqliteFixupHook() {
+      runtimeDependencies+=('${lib.getLib sqlite}')
+    }
+
+    preFixupHooks+=(sqliteFixupHook)
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p "$out"
+    ln -s '${src}'/* "$out"
+
+    runHook postInstall
+  '';
+}