MLBEDSW-7656: Update Python versions in README

 - Added Python support information
 - Clarified TensorFlow support information
 - Updated Requires-Python version to 3.8

Change-Id: Iab38a2f4480e58a1bd36d5055342c4bf7379dd09
Signed-off-by: Tim Hall <tim.hall@arm.com>
diff --git a/pyproject.toml b/pyproject.toml
index f2c5d60..e6428e4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@
 [project]
 name = "ethos-u-vela"
 description = "Neural network model compiler for Arm Ethos-U NPUs"
-requires-python = "~=3.7"
+requires-python = "~=3.8"
 authors = [{name = "Arm Ltd", email = "mlg-vela@arm.com"}]
 license = {text= "Apache License 2.0"}
 classifiers = [