ci: add GitHub Actions test workflow (#38)

* ci: add GitHub Actions test workflow

Add automated testing workflow that runs on push and pull requests
to main branch. Includes Go module caching and code coverage
reporting via Codecov.

* ci: update GitHub Actions to latest versions

Update actions/cache from v3 to v4 and codecov/codecov-action from v3 to v4.
Consolidate test steps to run tests with coverage in single step.

* Update .github/workflows/test.yaml

Co-authored-by: Copilot <[email protected]>

* ci: remove Go modules cache from test workflow

Remove caching step to simplify the workflow and avoid potential cache-related issues.

---------

Co-authored-by: Copilot <[email protected]>

Author: hrntknr

.github/workflows/test.yaml

@@ -0,0 +1,33 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: "1.23"
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Run tests
+        run: go test -v -coverprofile=coverage.out ./...
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}