allow remote_build on this host (server-arm), without conflicts of this "isabelle_self";

--- a/src/Pure/Admin/build_history.scala	Tue Jan 30 12:48:27 2024 +0100
+++ b/src/Pure/Admin/build_history.scala	Tue Jan 30 17:35:42 2024 +0100
@@ -537,6 +537,7 @@
     components_base: String = Components.dynamic_components_base,
     clean_platform: Boolean = false,
     clean_archives: Boolean = false,
+    shared_isabelle_self: Boolean = false,
     progress: Progress = new Progress,
     rev: String = "",
     afp_repos: Option[Path] = None,
@@ -556,7 +557,7 @@
         rev = rev, afp_rev = afp_rev, afp_root = if (afp) afp_repos else None)
     }
 
-    sync(isabelle_self)
+    if (!shared_isabelle_self) sync(isabelle_self)
 
     val self_isabelle =
       Other_Isabelle(isabelle_self, isabelle_identifier = isabelle_identifier,

--- a/src/Pure/Admin/isabelle_cronjob.scala	Tue Jan 30 12:48:27 2024 +0100
+++ b/src/Pure/Admin/isabelle_cronjob.scala	Tue Jan 30 17:35:42 2024 +0100
@@ -129,6 +129,7 @@
     history_base: String = "build_history_base",
     components_base: String = Components.dynamic_components_base,
     clean_components: Boolean = true,
+    shared_isabelle_self: Boolean = false,
     java_heap: String = "",
     options: String = "",
     args: String = "",
@@ -297,6 +298,7 @@
     List(
       List(Remote_Build("Linux (ARM)", "server-arm",
         history_base = "build_history_base_arm",
+        shared_isabelle_self = true,
         options = "-m32 -B -M1x2 -p timeout_scale=2" +
           " -e ISABELLE_SWIPL=swipl",
         args = "-a -d '~~/src/Benchmarks'")),
@@ -406,6 +408,7 @@
               components_base = r.components_base,
               clean_platform = r.clean_components,
               clean_archives = r.clean_components,
+              shared_isabelle_self = r.shared_isabelle_self,
               rev = rev,
               afp_repos = if (afp_rev.isDefined) Some(afp_repos) else None,
               afp_rev = afp_rev.getOrElse(""),