Ignore RuntimeError in AbstractConnection._close

[chbndrhnns]

Pull Request check-list

Please make sure to review and check all of these items:

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is there an example added to the examples folder (if applicable)?
• Was the change added to CHANGES file?

NOTE: these things are not required to open a PR and can be done
afterwards / while the PR is open.

Description of change

Fixes #3239 by ignoring a RuntimeError

[chbndrhnns]

@gerzse Could you help me proceed with this PR? It's my first one and I would like to know what needs to happen next from my side.

[chbndrhnns]

@vladvildanov Hi there, my very small PR seems to have gotten no attention in the last 5 months and I wanted to ask if there is something I could do about it?