Update CITATION.cff

Author: github-actions[bot]

CITATION.cff

@@ -8,7 +8,7 @@ message: 'To cite package "igraph" in publications use:'
 type: software
 license: GPL-2.0-or-later
 title: 'igraph: Network Analysis and Visualization'
-version: 1.6.0
+version: 1.6.0.9006
 abstract: Routines for simple graphs and network analysis. It can handle large graphs
   very well and provides functions for generating random and regular graphs, graph
   visualization, centrality methods and much more.
@@ -86,7 +86,7 @@ references:
   - family-names: Müller
     given-names: Kirill
   year: '2023'
-  notes: R package version 1.6.0
+  notes: R package version 1.6.0.9006
   doi: 10.5281/zenodo.7682609
   url: https://CRAN.R-project.org/package=igraph
 - type: software