Merge pull request #18832 from MrKevinWeiss/pr/removedrone

.drone: Remove unmaintained .drone file

.drone.yml

@@ -1,16 +0,0 @@
-pipeline:
-    run_tests:
-        image: riot/riotbuild:latest
-        environment:
-            - CLICOLOR_FORCE=1
-            - NPROC_MAX=4
-        commands:
-            - pwd
-            - printenv
-            - git status
-            - git remote -v
-            - ./dist/tools/ci/build_and_test.sh
-matrix:
-    BUILDTEST_MCU_GROUP:
-        - static-tests
-        - host