Change syslog dependency to Recommends

[braydonk]

Description

While a syslog daemon is required for full desired Ops Agent functionality, our previous reliance on the presence of a syslog daemon was provided by the dependency specified in the google-compute-engine package, which is a Recommends dependency.

This PR changes the syslog daemon dependency in the Ops Agent deb package to Recommends instead of Depends.

Related issue

b/339061751

How has this been tested?

Manually tested the workflow where we install Ops Agent without installing rsyslog:

make build to get a local deb package.
Created a new Debian 12 GCE VM.
Remove rsyslog from the VM:

sudo apt purge rsyslog

Copied the deb package to the VM. Install it without installing Recommended packages:

sudo apt install --no-install-recommends ./google-cloud-ops-agent_2.49.0~debian12_amd64.deb

rsyslog was not installed, verified with:

dpkg -l | grep rsyslog

Checklist:

• Unit tests
  • Unit tests do not apply.
  • Unit tests have been added/modified and passed for this PR.
• Integration tests
  • Integration tests do not apply.
  • Integration tests have been added/modified and passed for this PR.
• Documentation
  • This PR introduces no user visible changes.
  • This PR introduces user visible changes and the corresponding documentation change has been made.
• Minor version bump
  • This PR introduces no new features.
  • This PR introduces new features, and there is a separate PR to bump the minor version since the last release already.
  • This PR bumps the version.

[igorpeshansky]

LGTM

[braydonk]

Debian 11 failure is a flake. The rest of the failures are expected and unrelated to this change.

@igorpeshansky do you think this should be merged now or should we wait til those CI failures are resolved? This is slated for 2.49.0 but so are the fixes causing the CI failures in the PR anyway.

[igorpeshansky]

LGTM