[oomph] Update and cycle API baselines

Include 6.9.0, remove 6.6.0 API baseline. Include the 4.31 target
platform.

Change-Id: I0abf033667a2dbe62b437f04351f8e8cb2d084e7
Signed-off-by: Thomas Wolf <[email protected]>

tools/oomph/EGit.setup

@@ -132,17 +132,11 @@
     <choice
         value="egit-4.30"
         label="EGit 2023-12 (4.30) target"/>
+    <choice
+        value="egit-4.31"
+        label="EGit 2024-03 (4.31) target"/>
     <description>Default target platform for EGit development.</description>
   </setupTask>
-  <setupTask
-      xsi:type="pde:APIBaselineTask"
-      name="EGit"
-      activate="false"
-      version="6.6.0"
-      location="${workspace.location/../api.baseline/6.6.0}"
-      remoteURI="https://download.eclipse.org/egit/updates-6.6/org.eclipse.egit.repository-6.6.0.202305301015-r.zip">
-    <description>EGit 6.6.0 API baseline; to be used with branch stable-6.7</description>
-  </setupTask>
   <setupTask
       xsi:type="pde:APIBaselineTask"
       name="EGit"
@@ -155,11 +149,21 @@
   <setupTask
       xsi:type="pde:APIBaselineTask"
       name="EGit"
+      activate="false"
       version="6.8.0"
       location="${workspace.location/../api.baseline/6.8.0}"
       remoteURI="https://download.eclipse.org/egit/updates-6.8/org.eclipse.egit.repository-6.8.0.202311291450-r.zip">
-    <description>EGit 6.8.0 API baseline; to be used with branch master</description>
+    <description>EGit 6.8.0 API baseline; to be used with branch stable-6.9</description>
+  </setupTask>
+  <setupTask
+      xsi:type="pde:APIBaselineTask"
+      name="EGit"
+      version="6.9.0"
+      location="${workspace.location/../api.baseline/6.9.0}"
+      remoteURI="https://download.eclipse.org/egit/updates-6.9/org.eclipse.egit.repository-6.9.0.202403050737-r.zip">
+    <description>EGit 6.9.0 API baseline; to be used with branch master</description>
   </setupTask>
+
   <setupTask
       xsi:type="setup:CompoundTask"
       name="GerritHub">