MLECO-3213: Downgrade requirment from Python3.8 to Python3.7

Update Vela to 3.4.0

Signed-off-by: Richard Burton <richard.burton@arm.com>
Change-Id: If203d29d6884219cd4947a5753a1fb8d8284f174
diff --git a/set_up_default_resources.py b/set_up_default_resources.py
index c9f83c9..2d055ef 100755
--- a/set_up_default_resources.py
+++ b/set_up_default_resources.py
@@ -381,9 +381,9 @@
     metadata_file_path = download_dir / "resources_downloaded_metadata.json"
 
     metadata_dict = dict()
-    vela_version = "3.3.0"
-    py3_major_version_minimum = 3  # Python > 3.8 is required
-    py3_minor_version_minimum = 8
+    vela_version = "3.4.0"
+    py3_major_version_minimum = 3  # Python >= 3.7 is required
+    py3_minor_version_minimum = 7
 
     # Is Python minimum requirement matched?
     py3_version = sys.version_info
@@ -392,7 +392,7 @@
         or py3_version.minor < py3_minor_version_minimum
     ):
         raise Exception(
-            "ERROR: Python3.8+ is required, please see the documentation on how to update it."
+            "ERROR: Python3.7+ is required, please see the documentation on how to update it."
         )
 
     setup_script_hash_verified = False