ci: set sdkman_auto_answer in config file, not env

Author: pzalutski-pixel

.github/workflows/repro-issue18.yml

@@ -35,7 +35,7 @@ jobs:
       shell: /opt/homebrew/bin/bash -e {0}
       run: |
         curl -s "https://get.sdkman.io" | /opt/homebrew/bin/bash
-        export sdkman_auto_answer=true
+        sed -i.bak 's/sdkman_auto_answer=false/sdkman_auto_answer=true/' "$HOME/.sdkman/etc/config"
         source "$HOME/.sdkman/bin/sdkman-init.sh"
         # Match the reporter's full set of installed JDKs (his .install.xml lists all four).
         # Java 8 has a pre-module rt.jar layout — its presence changes JDT's VM reconciliation.