chore: Try updating Spoofax version

Unfortunately, Spoofax menu still not showing up.

.gitignore

@@ -5,7 +5,6 @@
 /site
 
 /.classpath
-/.project
 /.settings
 /.factorypath
 

.mvn/extensions.xml

@@ -3,6 +3,6 @@
   <extension>
     <groupId>org.metaborg</groupId>
     <artifactId>spoofax-maven-plugin-pomless</artifactId>
-    <version>2.5.13</version>
+    <version>2.6.0-SNAPSHOT</version>
   </extension>
 </extensions>

.project

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>spoofax_prop</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.m2e.core.maven2Builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.metaborg.spoofax.eclipse.meta.builder.generatesources</name>
+			<triggers>clean,full,</triggers>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.metaborg.spoofax.eclipse.builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.metaborg.spoofax.eclipse.meta.builder.prejava</name>
+			<triggers>clean,full,</triggers>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.metaborg.spoofax.eclipse.meta.builder.postjava</name>
+			<triggers>clean,full,</triggers>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.m2e.core.maven2Nature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+		<nature>org.metaborg.spoofax.eclipse.nature</nature>
+		<nature>org.metaborg.spoofax.eclipse.meta.nature</nature>
+	</natures>
+</projectDescription>

pom.xml

@@ -13,7 +13,7 @@
   <parent>
     <groupId>org.metaborg</groupId>
     <artifactId>parent.language</artifactId>
-    <version>2.5.13</version>
+    <version>2.6.0-SNAPSHOT</version>
   </parent>
   
   <repositories>