terraform test: don't remove sensitive marks from inputs

[liamcervante]

Previously, the Terraform plan functionality forbade input values with sensitive marks. The testing framework avoided this by removing the sensitive marks from inputs, and printing a warning if the input variable was not marked as sensitive. As of #34414 the terraform plan can now handle sensitive marks on input values. This means the testing framework no longer needs to remove sensitive marks, and warn users about the sensitive metadata being lost.

There's also a flyby refactoring of the tests in test_test.go to remove the init output from the expected/actual comparisons introduced as part of the recent init command refactoring. We don't care about validating the init output for theses tests.

Fixes #35011

Target Release

1.9.0

Draft CHANGELOG entry

ENHANCEMENTS

• terraform test: The test framework can now maintain sensitive metadata between run blocks.

[github-actions]

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[github-actions]

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