[CI] Delete node_modules in between bootstrap attempts (elastic#117588)…

… (elastic#118280)

Co-authored-by: Brian Seeders <[email protected]>

.buildkite/scripts/bootstrap.sh

@@ -5,7 +5,17 @@ set -euo pipefail
 source .buildkite/scripts/common/util.sh
 
 echo "--- yarn install and bootstrap"
-retry 2 15 yarn kbn bootstrap
+if ! yarn kbn bootstrap; then
+  echo "bootstrap failed, trying again in 15 seconds"
+  sleep 15
+
+  # Most bootstrap failures will result in a problem inside node_modules that does not get fixed on the next bootstrap
+  # So, we should just delete node_modules in between attempts
+  rm -rf node_modules
+
+  echo "--- yarn install and bootstrap, attempt 2"
+  yarn kbn bootstrap
+fi
 
 ###
 ### upload ts-refs-cache artifacts as quickly as possible so they are available for download