[DFT][rocFFT] Fix out-of-bounds stride handling

[zjin-lcf]

Summary

• avoid out-of-range std::array subscripts in rocFFT and DFT test stride handling, which abort 3-D transforms under checked standard libraries
• reject ranks above rocFFT's supported maximum instead of overflowing fixed-size storage
• correct forward/backward stride validation, packed-layout checks, and the rocFFT exception label

Test plan

• Run all rocFFT DFT functional tests on AMD Instinct MI300A with ROCm 7.2.4: 667 passed, 272 skipped, 0 failed
• Repeat the full suite with -D_GLIBCXX_ASSERTIONS: 667 passed, 272 skipped, 0 failed
• Verify baseline and fixed runs have identical skipped-test lists
• Verify 1-D, 2-D, and 3-D descriptor commits succeed under checked libstdc++; 4-D and 5-D commits throw unimplemented
• Run the pre-commit clang-format hook