Use variable for the path to Aviso files

This variable was already used in other tests.

Inst_eddies/Tests/short_tests.json

@@ -434,7 +434,7 @@
 	[
             [
 		"ncpdq", "-U", "-h",
-		"/proju/lmd-oce/data/AVISO/DT_2018/All_SymbolicLinks/dt_global_allsat_phy_l4_20060112_20210726.nc",
+		"$Aviso_DT_dir/dt_global_allsat_phy_l4_20060112_20210726.nc",
 		"--dimension=longitude,0.125,29.875",
 		"--dimension=latitude,-59.875,-15.125", "plouf.nc"
 	    ],
@@ -455,7 +455,7 @@
 	[
             [
 		"ncpdq", "-U", "-h",
-		"/proju/lmd-oce/data/AVISO/DT_2018/All_SymbolicLinks/dt_global_allsat_phy_l4_20060103_20210726.nc",
+		"$Aviso_DT_dir/dt_global_allsat_phy_l4_20060103_20210726.nc",
 		"--dimension=longitude,0.125,29.875",
 		"--dimension=latitude,-59.875,-15.125", "plouf.nc"
 	    ],