chore: fix "A mapping was not expected" error

See actions/runner#2289 (comment)

Corrections for d1fd249 commit.

Relate to #1350 #1158 #1556

Author: php-coder

Diff for: .github/workflows/integration-tests-h2.yml

@@ -33,7 +33,7 @@ jobs:
           - java-version: '17'
             allow-failure: true
     # https://docs.github.com/en/actions/using-jobs/using-a-matrix-for-your-jobs#handling-failures
-    continue-on-error: {{ matrix.allow-failure }}
+    continue-on-error: ${{ matrix.allow-failure }}
     steps:
       - name: Clone source code
         uses: actions/[email protected] # https://github.com/actions/checkout