ci: use uv to install gcovr and sphinx

Change-Id: I560f2e32374e03be463c843823749de21bbe74f8
diff --git a/docs/INSTALL.rst b/docs/INSTALL.rst
index b104041..82fa64b 100644
--- a/docs/INSTALL.rst
+++ b/docs/INSTALL.rst
@@ -83,7 +83,7 @@
 
 - doxygen
 - graphviz
-- sphinx >= 4.0
+- sphinx
 - sphinxcontrib-doxylink
 
 The following lists the steps to install these prerequisites on various common platforms.
@@ -101,21 +101,21 @@
   .. code-block:: sh
 
     sudo apt install doxygen graphviz python3-pip
-    pip3 install --user sphinx sphinxcontrib-doxylink
+    python3 -m pip install --user -r docs/requirements.txt
 
 - On **CentOS** and **Fedora**:
 
   .. code-block:: sh
 
     sudo dnf install doxygen graphviz python3-pip
-    pip3 install --user sphinx sphinxcontrib-doxylink
+    python3 -m pip install --user -r docs/requirements.txt
 
 - On **macOS**:
 
   .. code-block:: sh
 
     brew install doxygen graphviz
-    sudo pip3 install sphinx sphinxcontrib-doxylink
+    python3 -m pip install --user -r docs/requirements.txt
 
 - On **FreeBSD**: