[DOCS] #4587 – Make Sphinx warnings break docs build

Lock readme-renderer version to <25.0 as starting with v25 Python 3.4 is not supported anymore.

requirements.d/development.lock.txt

@@ -10,3 +10,4 @@ pytest-cov==2.6.1
 pytest-benchmark==3.2.2
 Cython==0.29.6
 twine==1.13.0
+readme-renderer<25.0

requirements.d/development.txt

@@ -9,3 +9,4 @@ pytest-cov
 pytest-benchmark
 Cython!=0.27
 twine
+readme-renderer<25.0