[#908] Prepare 4.9.0 M1 contribution

* Platform
* EGit
* EMF
* CDT

Author: ruspl-afed

org.eclipse.mylyn-target/org.eclipse.mylyn.target.target

@@ -20,7 +20,7 @@
 			<unit id="org.eclipse.license.feature.group" version="0.0.0"/>
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/eclipse/updates/4.38-I-builds"/>
+			<repository location="https://download.eclipse.org/eclipse/updates/4.38-I-builds/I20251003-1800/"/>
 			<unit id="org.eclipse.equinox.sdk.feature.group" version="0.0.0"/>
 			<unit id="org.eclipse.equinox.p2.sdk.feature.group" version="0.0.0"/>
 			<unit id="org.eclipse.sdk.feature.group" version="0.0.0"/>
@@ -30,21 +30,21 @@
 			<unit id="org.eclipse.egit.github.core" version="0.0.0"/>
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/egit/updates-7.4/"/>
+			<repository location="https://download.eclipse.org/egit/staging/v7.5.0.202510071400-m1/"/>
 			<unit id="org.eclipse.egit.feature.group" version="0.0.0"/>
 			<unit id="org.eclipse.jgit.feature.group" version="0.0.0"/>
 			<unit id="org.eclipse.jgit.lfs.feature.group" version="0.0.0"/>
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/modeling/emf/emf/builds/release/2.43.0/"/>
+			<repository location="https://download.eclipse.org/modeling/emf/emf/builds/milestone/S202509240621/"/>
 			<unit id="org.eclipse.emf.sdk.feature.group" version="0.0.0"/>
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
 			<repository location="https://download.eclipse.org/rt/ecf/3.16.5/site.p2/3.16.5.v20250914-0333/"/>
 			<unit id="org.eclipse.ecf.remoteservice.sdk.feature.feature.group" version="0.0.0"/>
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/tools/cdt/builds/12.2/cdt-12.2.0-rc2/"/>
+			<repository location="https://download.eclipse.org/tools/cdt/builds/12.3/cdt-12.3.0-m1/"/>
 			<unit id="org.eclipse.cdt.platform.feature.group" version="0.0.0"/>
 			<unit id="org.eclipse.cdt.sdk.feature.group" version="0.0.0"/>
 		</location>