File cache in CodeAnalysisRuleSetPredictor does not consider the rule set directories

[stan-sz]

The cache hit is based on file path

MSBuildPrediction/src/BuildPrediction/Predictors/CodeAnalysisRuleSetPredictor.cs

Line 151 in f852f03

if (_cachedInputs.TryGetValue(ruleSetPath, out HashSet<string> cachedResults))

however some projects may load the same ruleset file with different value of CodeAnalysisRuleSetDirectories. In case a ruleset file with includes and empty CodeAnalysisRuleSetDirectories is parsed (and cached), the included will be omitted. Subsequent parsing of the same ruleset file, will yield the same, small set of inputs, despite the fact that they may provide more directories in CodeAnalysisRuleSetDirectories.

[stan-sz]

This issue covers the ruleset directories. There's also a factor of environment variables expansion during include processing.