Hotfix: don't retry endlessly on verifier errors on kernels <6.4

During the prior removal of ProgramOptions.LogSize in v0.16, the tests weren't updated to exercise the retry logic. With the last-minute addition of ProgramOptions.LogSizeStart, a bug was introduced that would cause program loads to retry indefinitely without ever growing the buffer in case of a verifier error on kernels before 6.4. This is now fixed, and the tests were updated to exercise the retry logic.

• prog: fix shadowing log size variable in verifier log retry loop by @ti-mo in #1635