[2.4.0] Checkmk Werk 16892 created: agent_kube: requests.SSLError raised on connection using self signed certificates

[//]: # (werk v2) # agent_kube: requests.SSLError raised on connection using self signed certificates key | value ---------- | --- compatible | yes version | 2.4.0b1 date | 2024-09-02T12:01:17+00:00 level | 1 class | fix component | checks edition | cre Newer versions of `requests` don't take `REQUESTS_CA_BUNDLE` into account, resulting in ``` requests.exceptions.SSLError: \ HTTPSConnectionPool(host='<collector>', port=443): \ Max retries exceeded with url: \ /metadata (Caused by SSLError( \ SSLCertVerificationError(1, \ '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: \ self signed certificate in certificate chain (_ssl.c:1006)'))) ``` being raised if running `agent_kube` against instances using self signed certificates. This change invokes `session.merge_environment_settings()` to take `REQUESTS_CA_BUNDLE` into account again. See [GitHub: 2807: Use merge_environment_settings method in sessions.send method](https://github.com/psf/requests/issues/2807) and [GitHub: 3626: HTTP Proxy with prepared request (honouring env. var.)](https://github.com/psf/requests/issues/3626)