Update Gaudi to v39r4.000

Update Gaudi version to v39r4.000

Release notes: https://gitlab.cern.ch/gaudi/Gaudi/-/releases/v39r4

Projects/AthAnalysis/build_externals.sh

@@ -12,7 +12,7 @@ ATLAS_BUILDTYPE="Release"
 ATLAS_EXTRA_CMAKE_ARGS=(-DLCG_VERSION_NUMBER=107
                         -DLCG_VERSION_POSTFIX="a_ATLAS_1"
                         -DATLAS_ONNXRUNTIME_USE_CUDA=FALSE
-                        -DATLAS_GAUDI_SOURCE="URL;https://gitlab.cern.ch/atlas/Gaudi/-/archive/v39r2.000/Gaudi-v39r2.000.tar.gz;URL_MD5;72cf6f13c9461ab0a0e8447af80e092b")
+                        -DATLAS_GAUDI_SOURCE="URL;https://gitlab.cern.ch/atlas/Gaudi/-/archive/v39r4.000/Gaudi-v39r4.000.tar.gz;URL_MD5;abe78ac62447548328d563201e0018d4")
 ATLAS_EXTRA_MAKE_ARGS=()
 
 # Let "the common script" do all the heavy lifting.