FIX Support Diagnostics housekeeping

The diagnostics dump job splits collecting data into chunks and creates
a tar for each chunk. The internal housekeeping, on the other hand, only
keeps 5 tar files.
So, when lots of options are selected to be included into the dump, the
tars were deleted before they were collected.

Reference: CMK-20621

The number of tars to keep is now set to 10.

Change-Id: If96f97a95958824ffcc72deb44b70f9bc287e02c

cmk/base/diagnostics.py

@@ -136,7 +136,7 @@ def _format_error(error):
 class DiagnosticsDump:
     """Caring about the persistance of diagnostics dumps in the local site"""
 
-    _keep_num_dumps = 5
+    _keep_num_dumps = 10
 
     def __init__(self, parameters: DiagnosticsOptionalParameters | None = None) -> None:
         self.fixed_elements = self._get_fixed_elements()