Fixes support for syslog when salt is running as non-root user

[shadow38]

What does this PR do?

Adds support for file:// scheme in syslog handler configuration.

What issues does this PR fix or reference?

Closes #68801 (previous PR targeting master, reopened for 3006.x as requested by @dwoz)

Previous Commits

Cherry-picked from previous PR #68801 and rebased onto 3006.x

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