[Build] Remove unusable 'api-problems'-matcher for shared GH workflows

The defined pattern seems not to match and cannot easily be fixed.
And because in Jenkins API-problems are displayed more reliably, the
entire matcher is just removed.

Author: HannesWell

.github/matcher/api-tools.json

@@ -84,11 +84,6 @@ jobs:
       with:
         tycho-version: 4.0.12
 
-    - name: Download the API Tools matcher
-      run: |
-        mkdir .github/matcher
-        curl -o .github/matcher/api-tools.json https://raw.githubusercontent.com/eclipse-platform/eclipse.platform.releng.aggregator/master/.github/matcher/api-tools.json
-        echo "::add-matcher::.github/matcher/api-tools.json"
     - name: Build with Maven
       run: >-
         ${{ runner.os == 'Linux' && 'xvfb-run' || '' }}