build: fix @microsoft/api-extractor version to 7.19.x (#49)
build: fix @microsoft/api-extractor version to 7.19.x (#49)

We should fix our @microsoft/api-extractor version to the last working version that is compatible with our [api-documenter fork](https://github.com/googleapis/rushstack/tree/main/apps/api-documenter). We can relax version constraints once we put tests in place to ensure any version updates do not break our yaml generation.
googleapis/nodejs-cloud-rad,googleapis/nodejs-cloud-rad,googleapis/nodejs-cloud-rad