fix(docs): python version must be string

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: If5886f8adb391edf3771112cd8e20957a454eae0
(cherry picked from commit 3aa919eb278e7e0b23742ea043d79e1b1f1d75c6)
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 99525b5..3663f37 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -12,7 +12,7 @@
 build:
   os: ubuntu-22.04 # Ubuntu Jammy LTS
   tools:
-    python: 3.10
+    python: "3.10"
 
 python:
   install: