refactor(uart): Refactor UART test to work with any number of UARTs (#10593)

* refactor(uart): Refactor UART test to work with any number of UARTs

Co-authored-by: Rodrigo Garcia <[email protected]>

* fix(uart): Set CPU freq on ESP32

* ci(pre-commit): Apply automatic fixes

* fix(spelling): Fix codespell error

---------

Co-authored-by: Rodrigo Garcia <[email protected]>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

Author: 3 people

Diff for: tests/validation/uart/diagram.esp32.json

@@ -0,0 +1,24 @@
+{
+  "version": 1,
+  "author": "lucasssvaz",
+  "editor": "wokwi",
+  "parts": [
+    {
+      "type": "board-esp32-devkit-c-v4",
+      "id": "esp",
+      "attrs": { "cpuFrequency": "40" }
+    }
+  ],
+  "connections": [
+    [
+      "esp:TX",
+      "$serialMonitor:RX",
+      ""
+    ],
+    [
+      "esp:RX",
+      "$serialMonitor:TX",
+      ""
+    ]
+  ]
+}