Use ismethod to detect methods used as a transformation

[Kody-Quintana]

Proposed changes

This changes the value that is used to compare against the number of args of a transformation callable's arg spec when determining whether or not to call the transformation with t(obj, opts) or just t(obj).

The returned value from len(getfullargspec(t)[0]) will include the self and cls args from a method, but when calling a method the first argument is implicitly added so if you use a method for t it will fail.

This changes the value to be 3 if t is a method.

Related issues (optional)

Fix #2468

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[lblackstone]

/run-acceptance-tests

[pulumi-bot]

Please view the PR build: https://github.com/pulumi/pulumi-kubernetes/actions/runs/5393036987

[lblackstone]

Thanks for the thorough writeup and fix @Kody-Quintana! I kicked off the CI tests to check, but the code change LGTM.

[github-actions]

PR is now waiting for a maintainer to run the acceptance tests.
Note for the maintainer: To run the acceptance tests, please comment /run-acceptance-tests on the PR

[github-actions]

PR is now waiting for a maintainer to run the acceptance tests.
Note for the maintainer: To run the acceptance tests, please comment /run-acceptance-tests on the PR

[Kody-Quintana]

Thanks for taking the time to look at this, very appreciated