GHSA-w34q-cm8f-9c5x: OpenTelemetry-Go: Log gRPC exporter ignores env TLS certs, bypassing mTLS/pinning

The OpenTelemetry-Go library's log gRPC exporter reads TLS settings from environment variables (like OTEL_EXPORTER_OTLP_LOGS_CERTIFICATE for CA pinning and client certificates for mTLS, which is mutual TLS authentication between two systems) but then ignores them when actually connecting. Instead, it uses the system's default trusted certificates, allowing an attacker with a valid system certificate to intercept or alter log data. This bug was introduced in a specific code commit and affects users who only set TLS through environment variables without also using explicit code configuration.