Relicense Remaining LGPL-2.0-only Code: KConfigWidgets

src/kstandardaction_p.h:    SPDX-License-Identifier: LGPL-2.0-only
src/krecentfilesaction_p.h:    SPDX-License-Identifier: LGPL-2.0-only
src/kpastetextaction.cpp:    SPDX-License-Identifier: LGPL-2.0-only
src/krecentfilesaction.cpp:    SPDX-License-Identifier: LGPL-2.0-only
src/kstandardaction.h:    SPDX-License-Identifier: LGPL-2.0-only
src/khelpclient.h:    SPDX-License-Identifier: LGPL-2.0-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
src/krecentfilesaction.h:    SPDX-License-Identifier: LGPL-2.0-only
src/kstandardaction.cpp:    SPDX-License-Identifier: LGPL-2.0-only
src/khelpclient.cpp:    SPDX-License-Identifier: LGPL-2.0-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
src/kpastetextaction.h:    SPDX-License-Identifier: LGPL-2.0-only