Update to Tycho 4.0.1

Tycho 4.0.0-SNAPSHOT is no longer available and it's a bad practice to
depend on any snapshot version (we had to since this was the only way
to get gpg signing to work in time for releasing 6.6.0).

Change-Id: I1d4af5f69965b4cad50b379fd81f6f442b38c8d0

org.eclipse.jgit.packaging/pom.xml

diff --git a/org.eclipse.jgit.packaging/pom.xml b/org.eclipse.jgit.packaging/pom.xml
index a2ab65c..f310711 100644
--- a/org.eclipse.jgit.packaging/pom.xml
+++ b/org.eclipse.jgit.packaging/pom.xml
@@ -23,7 +23,7 @@
 
   <properties>
     <java.version>11</java.version>
-    <tycho-version>4.0.0-SNAPSHOT</tycho-version>
+    <tycho-version>4.0.1</tycho-version>
     <target-platform>jgit-4.17</target-platform>
   </properties>