docs: note CMake >= 3.30 requirement in prerequisites (#3022)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: FIM43-Redeye

README.md

@@ -108,6 +108,14 @@ xrt-smi examine
     build-essential clang clang-14 lld lld-14 cmake ninja-build python3-venv python3-pip
     ```
 
+    > **Note:** CMake **3.30 or newer** is required. If your distribution provides an older
+    > version, create and activate the Python virtual environment in the setup step below
+    > first, then install a newer CMake into that virtual environment:
+    >
+    > ```bash
+    > python3 -m pip install --upgrade cmake
+    > ```
+
 1. (Optional) Install opencv which is needed for vision programming examples:
 
    ```bash

docs/README.md

@@ -76,6 +76,14 @@ Turn off SecureBoot (Allows for unsigned drivers to be installed):
     build-essential clang clang-14 lld lld-14 cmake ninja-build python3-venv python3-pip
     ```
 
+    > **Note:** CMake **3.30 or newer** is required. If your distribution provides an older
+    > version, create and activate the Python virtual environment in the setup step below
+    > first, then install a newer CMake into that virtual environment:
+    >
+    > ```bash
+    > python3 -m pip install --upgrade cmake
+    > ```
+
 1. (Optional) Install opencv which is needed for vision programming examples:
 
    ```bash