feat(opentelemetry-node): include OTEL_ and ELASTIC_OTEL_ envvars in preamble log.info

[trentm]

This includes all likely to be relevant envvars in the preamble log
message to help with clarity and debugging. The value of envvars are
included if they are on the allowlist of known to not be sensitive
envvars. Otherwise the value is redacted.

(I think there would still be value to a string representation of the
SDK components. However that is larger work that could be done
separately.)

Closes: #1018

[trentm]

Here is an example. I have a few o... aliases (e.g. oquiet and opamp) that I use for setting some convenience envvars to configure EDOT Node.js and OTel JS for local dev. Now the preamble conveniently shows the actual envvars that were set:

% ofast opamp  oquiet npm run example | pino-pretty

> @elastic/[email protected] example
> cd ../../examples && node --import @elastic/opentelemetry-node simple-http-request.js

[12:31:58.616] WARN (elastic-otel-node): Unsupported OTLP metrics protocol: "undefined". Using http/protobuf.
[12:31:58.620] INFO (elastic-otel-node): start EDOT Node.js
    preamble: true
    distroVersion: "1.6.0"
    system: {
      "os": "darwin 24.6.0",
      "arch": "arm64",
      "runtime": "Node.js v20.19.1"
    }
    edotEnv: {
      "OTEL_METRIC_EXPORT_TIMEOUT": "5000",
      "OTEL_NODE_DISABLED_INSTRUMENTATIONS": "dns,net,runtime-node",
      "ELASTIC_OTEL_HOST_METRICS_DISABLED": "true",
      "ELASTIC_OTEL_OPAMP_ENDPOINT": "http://localhost:4320",
      "OTEL_METRIC_EXPORT_INTERVAL": "5000",
      "OTEL_NODE_RESOURCE_DETECTORS": "env,host,os,process,serviceinstance",
      "ELASTIC_OTEL_EXPERIMENTAL_OPAMP_HEARTBEAT_INTERVAL": "5000"
    }
    configInfo: {
      "logLevel": "info"
    }
...

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