deps(dotnet): updated NLog.WindowsEventLog to 6.1.3

PR #77 bumped NLog and NLog.Extensions.Logging from 6.1.2 to
6.1.3; the sibling NLog.WindowsEventLog stayed at 6.1.2 because
the parallel Dependabot PR #78 — which also covered the
WindowsEventLog bump — was auto-closed after #77 merged
(Dependabot detected the NLog line was already at 6.1.3 and
treated #78 as superseded, without separately handling the
WindowsEventLog line that was unique to #78).

* Three NLog 6.1.x packages now consistently at 6.1.3
  (NLog, NLog.Extensions.Logging, NLog.WindowsEventLog)
* The NLog.Targets.* family stays on 6.0.x / 6.1.1 by
  intent (per inline comment "NLog 6.0 separate target
  packages") — no 6.1.3 release exists for those
* Local build green on net8 + net10

Author: karlspace

Directory.Packages.props

@@ -8,7 +8,7 @@
     <!-- Core / Utilities -->
     <PackageVersion Include="NLog" Version="6.1.3" />
     <PackageVersion Include="NLog.Extensions.Logging" Version="6.1.3" />
-    <PackageVersion Include="NLog.WindowsEventLog" Version="6.1.2" />
+    <PackageVersion Include="NLog.WindowsEventLog" Version="6.1.3" />
     <!-- NLog 6.0 separate target packages -->
     <PackageVersion Include="NLog.Targets.Mail" Version="6.1.1" />
     <PackageVersion Include="NLog.Targets.Network" Version="6.0.4" />