Make sure to add a new line at the end of XML files

csharp/Google.Protobuf.Tools.nuspec

@@ -36,4 +36,4 @@
     <file src="Google.Protobuf.Tools.targets" target="buildCrossTargeting"/>
     <file src="Google.Protobuf.Tools.targets" target="build"/>
   </files>
-</package>
+</package>

csharp/src/Google.Protobuf/Google.Protobuf.csproj

@@ -33,4 +33,4 @@
     <PackageReference Include="SourceLink.Create.CommandLine" PrivateAssets="All" Version="2.7.6"/> 
   </ItemGroup>
 
-</Project>
+</Project>

java/core/pom.xml

@@ -154,4 +154,4 @@
     </plugins>
   </build>
 
-</project>
+</project>

java/pom.xml

@@ -216,4 +216,4 @@
     <module>util</module>
   </modules>
 
-</project>
+</project>

java/util/pom.xml

@@ -126,4 +126,4 @@
       </plugin>
     </plugins>
   </build>
-</project>
+</project>

protoc-artifacts/pom.xml

@@ -131,4 +131,4 @@
       </build>
     </profile>
   </profiles>
-</project>
+</project>

update_version.py

@@ -53,6 +53,7 @@ def RewriteXml(filename, rewriter, add_xml_prefix=True):
   if add_xml_prefix:
     file_handle.write('<?xml version="1.0" encoding="UTF-8"?>\n')
   file_handle.write(content)
+  file_handle.write('\n')
   file_handle.close()