cli: release 3.19.1

[bassosimone]

The objective of this release is to include the signal fix https://github.com/ooni/probe-cli/pull/1389 plus other minimal work to update geoip databases etc. We'll merge to master first, then backport to the release branch and tag a release.

• [x] merge https://github.com/ooni/probe-cli/pull/1389
• [x] merge https://github.com/ooni/spec/pull/281
• [x] backport https://github.com/ooni/probe-cli/pull/1389:
• [x] probe-cli: update bundled certs (using go generate ./...): done, no changes!
• [x] probe-cli: update github.com/ooni/probe-assets dependency
• [x] probe-cli: make sure all workflows are green
• [x] probe-cli: go test -race -count 1 ./... must pass locally
• [x] probe-cli: tag a new version
• [x] probe-cli: update internal/version/version.go
• [x] android: publish packages
• [x] iThena: notify about new release
• [x] debian: publish packages

[bassosimone]

Done!