Add code coverage reporting to CI with Codecov integration

[Copilot]

Extends CI pipeline to generate coverage reports and publish to https://app.codecov.io/gh/falkordb/falkordb-go.

Changes

• Modified test step to generate coverage with -coverprofile=coverage.txt -covermode=atomic
• Added race detection with -race flag
• Integrated codecov/codecov-action@v5 to upload coverage reports
• Configured with fail_ci_if_error: false to prevent CI failures from Codecov unavailability

Setup Required

Repository maintainers need to configure CODECOV_TOKEN secret:

1. Obtain upload token from https://app.codecov.io/gh/falkordb/falkordb-go
2. Add as repository secret named CODECOV_TOKEN

The README already contains the Codecov badge which will activate once coverage uploads begin.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add code coverage</issue_title>
<issue_description>Extend the CI to generate code coverage and publish to codecov

Publish code coverage to https://app.codecov.io/gh/falkordb/falkordb-go</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add code coverage #70

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}