[releng] Update the tycho/signing versions

Simplify the target platform.
diff --git a/releng/org.eclipse.emf.parent/pom.xml b/releng/org.eclipse.emf.parent/pom.xml
index 8731078..8bae274 100644
--- a/releng/org.eclipse.emf.parent/pom.xml
+++ b/releng/org.eclipse.emf.parent/pom.xml
@@ -11,8 +11,8 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <tycho.scmUrl>scm:git:https://git.eclipse.org/r/p/emf/org.eclipse.emf.git</tycho.scmUrl>
-    <tycho-version>2.7.3</tycho-version>
-    <jarsigner-version>1.3.1</jarsigner-version>
+    <tycho-version>2.7.5</tycho-version>
+    <jarsigner-version>1.3.2</jarsigner-version>
     <javaVersion>11</javaVersion>
     <os-jvm-flags/>
   </properties>
diff --git a/releng/org.eclipse.emf.parent/tp/2023-03.target b/releng/org.eclipse.emf.parent/tp/2023-03.target
index 37ef100..c317616 100644
--- a/releng/org.eclipse.emf.parent/tp/2023-03.target
+++ b/releng/org.eclipse.emf.parent/tp/2023-03.target
@@ -29,8 +29,6 @@
 
       <repository location="https://download.eclipse.org/rt/rap/3.10/R-20190911-1524"/>
 
-      <repository location="https://download.eclipse.org/modeling/emf/emf/builds/milestone/latest"/>
-
       <repository location="https://download.eclipse.org/nebula/releases/2.2.0"/>
 
     </location>