fix(logger): reset log level after sampling refresh

[dreamorosi]

Summary

Changes

Please provide a summary of what's being changed

This PR fixes a bug with the log sampling feature in Logger that was introduced in v2 and that caused log sampling to stay enabled within the same execution environment after the first time an invocation was sampled.

I fixed the bug by storing the initial log level in a private property within the logger instance and then using this initial log level to restore the log level whenever the sampling calculation is not sampled.

Please add the issue number below, if no issue is present the PR might get blocked and not be reviewed

Issue number: #2668

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[dreamorosi]

Integration tests passing: https://github.com/aws-powertools/powertools-lambda-typescript/actions/runs/9566448596

[heitorlessa]

suuuperb investigation of one those bugs that look obvious when we find the root cause, but difficult without customer feedback and/or maintainer having quality time to get a feature scrutinized and peer reviewed.

As we briefly discussed on a call, two things we need to keep in mind:

1. This feature will be superseded by a proper well established solution -- buffering debug logs (have and eat the cake too)

2. It looks like Logger for TS could beneift from a "Handler" responsibility to eventually keep the Logger interface cleaner

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud