LICENSE.txt: Added attribution of new test projects for NUnit extensions

LICENSE.txt

@@ -735,6 +735,8 @@ Some code in
 src/Lucene.Net.TestFramework/Support/Util/DefaultNamespaceTypeWrapper.cs
 src/Lucene.Net.TestFramework/Support/Util/LuceneTestCase.TestFixtureAttribute.cs
 src/Lucene.Net.TestFramework/Support/Util/NUnitTestFixtureBuilder.cs
+src/dotnet/Lucene.Net.TestFramework.TestData.NUnit/*
+src/Lucene.Net.Tests.TestFramework.NUnitExtensions/*
 falls under the following license:
 
 // Copyright (c) 2021 Charlie Poole, Rob Prouse
@@ -798,4 +800,4 @@ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (
 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
-ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.