logging: close file handle on permission errors when not rolling (#7833)

[vvdvortsova]

I'm not a native English speaker, so I used AI to help translate this PR description. The code and analysis are my own.

Fix resource leak in OpenWriter.
Fix for issue #7833.

What

In FileWriter.OpenWriter (modules/logging/filewriter.go), when roll: false and a custom mode is configured, the function could return early (on a Stat or Chmod error) without ever closing the previously opened file, leaking the descriptor. Added file.Close() on both error-return paths inside that block. The success path (returning the open file handle to the caller when !roll) is left untouched, since that handle is intentionally returned open to the caller.

Testing
go build ./modules/logging/...
go vet ./modules/logging/...

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