[sdk] Remove redundant NotNullWhen in SelfDiagnosticsConfigParser.TryParseLogDirectory

[SimonCropp]

Changes

logDirectoryResult.Groups["LogDirectory"].Value; can never return null. which is clear by the fact that string logDirectory is not string? logDirectory and it doesnt warn.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[Kielek]

I am fine with this or, whole method as

    internal static bool TryParseLogDirectory(
        string configJson,
        [NotNullWhen(true)]
        out string? logDirectory)
    {
        var logDirectoryResult = LogDirectoryRegex.Match(configJson);
        if (!logDirectoryResult.Success)
        {
            logDirectory = null;
            return false;
        }

        logDirectory = logDirectoryResult.Groups["LogDirectory"].Value;
        return !string.IsNullOrWhiteSpace(logDirectory);
    }

[SimonCropp]

in keeping with "make smallest possible change to fix a problem" i would prefer to leave the PR as is. would prefer a lerger cleanup of the method to be done in a diff PR

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.39%. Comparing base (54f7d9e) to head (e40329b).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6073   +/-   ##
=======================================
  Coverage   86.39%   86.39%           
=======================================
  Files         257      257           
  Lines       11650    11650           
=======================================
  Hits        10065    10065           
  Misses       1585     1585           

Files with missing lines	Coverage Δ
...nTelemetry/Internal/SelfDiagnosticsConfigParser.cs	85.71% <ø> (ø)