Add GitHub action for running TAP tests.

.github/workflows/run-tap-tests.yml

@@ -0,0 +1,22 @@
+---
+name: Run tap tests
+
+on:
+  - push
+  - pull_request
+  # Allow manually triggering the workflow.
+  - workflow_dispatch
+
+# Cancels all previous workflow runs for the same branch that have not yet completed.
+concurrency:
+  # The concurrency group contains the workflow name and the branch name.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: npm install
+      - run: ./node_modules/.bin/tap --color --reporter=base test/*.mjs