Merge pull request #6343 from Ouss4/dummy-selfhosted

.github/workflows: Remove the slefhost runner test.

.github/workflows/test_selfhosted_runner.yml

-name: Test Github action on self hosted RPI runnes
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-
-jobs:
-  build:
-    name: Dummy test - self hosted GHR
-    runs-on: self-hosted
-    if: github.repository == 'espressif/arduino-esp32'
-    steps:
-      - name: Check out repo
-        uses: actions/checkout@v2
-      - name: Test message 1
-        run: echo "This is test message"
-      - name: Test message 2
-        run: echo "This is test message2"
-      - name: List directory
-        run: ls
-      - name: Create copy of README
-        run: cp README.md README2.md
-      - name: Read README2
-        run: cat README2.md
-      - name: Delete README2
-        run: rm README2.md