Warn only once about deprecated rules.

[UncleOwen]

See pmd/pmd#6610

PmdAnalysis.create() already warns about deprecated rules. No need to load them twice, just to trigger the warning.

Added an integration test that is basically a copy of MPMD-268-deprecated-rules - just checks for exactly one log message instead of at least one.

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[slawekjaranowski]

Added an integration test that is basically a copy of MPMD-268-deprecated-rules - just checks for exactly one log message instead of at least one.

now I see we have the seme test.
I would like to change asertion in existing instead of adding a copy

[UncleOwen]

Fine with me :)

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@slawekjaranowski Please assign appropriate label to PR according to the type of change.