fix(readme): point the CodeQL badge at the workflow that runs it

The badge used the github-code-scanning/codeql path, which is where
GitHub's default setup publishes. This repository runs CodeQL from its
own .github/workflows/codeql.yml, so that URL had no run to report and
the badge rendered "CodeQL - no status".

Verified against both URLs: the old one returns a badge titled
"CodeQL - no status", the new one "CodeQL - passing".

Signed-off-by: Sebastian Mendel <github@sebastianmendel.de>

Author: CybotTM

README.md

@@ -7,7 +7,7 @@
 [![CI](https://github.com/netresearch/ofelia/actions/workflows/ci.yml/badge.svg)](https://github.com/netresearch/ofelia/actions/workflows/ci.yml)
 [![CodSpeed](https://img.shields.io/endpoint?url=https://codspeed.io/badge.json&style=flat&label=benchmarks&logo=codspeed)](https://codspeed.io/netresearch/ofelia)
 [![codecov](https://codecov.io/gh/netresearch/ofelia/graph/badge.svg)](https://codecov.io/gh/netresearch/ofelia)
-[![CodeQL](https://github.com/netresearch/ofelia/actions/workflows/github-code-scanning/codeql/badge.svg)](https://github.com/netresearch/ofelia/actions/workflows/github-code-scanning/codeql)
+[![CodeQL](https://github.com/netresearch/ofelia/actions/workflows/codeql.yml/badge.svg)](https://github.com/netresearch/ofelia/actions/workflows/codeql.yml)
 [![GitHub release](https://img.shields.io/github/v/release/netresearch/ofelia)](https://github.com/netresearch/ofelia/releases/latest)
 [![Go Version](https://img.shields.io/github/go-mod/go-version/netresearch/ofelia)](go.mod)
 [![License](https://img.shields.io/github/license/netresearch/ofelia)](LICENSE)