Add ORT_HOME_PATH/cache to the locations for the GH cache

[netomi]

Some package managers store downloaded artifacts in the ORT_HOME_PATH/cache directory for faster access after the first run, one example being the maven package manager.

Adding the .m2 directory as cache is not sufficient in this case, as the package manager will do a head request for all artifacts all the time unless it is found in the aforementioned cache.

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[sschuberth]

Is this the (only) root cause of the slowness compared to pure Maven you mentioned over here?

[netomi]

No that would only make subsequent runs of the action faster imho. The initial run might still be slow. However, I am not sure if this PR makes sense atm, as I realized that the cache is initialized by default with a maxCacheEntryAgeInSeconds of 6h.

[sschuberth]

However, I am not sure if this PR makes sense atm, as I realized that the cache is initialized by default with a maxCacheEntryAgeInSeconds of 6h.

I guess it cannot hurt anyway.