[CK_BUILDER] Fix two staging-compiler errors in CK builder
code (#4598)
This PR fixes two compiler warnings that report as errors with the
latest compiler:
1. In tensor descriptor, the `operator[]` accessor needs a
`[[clang::lifetimebound]]` attribute.
2. In the unit tests for device buffer, there is a test that explicitly
checks for an error on a pointer that went out of scope, so it needs a
to disable `-Wlifetime-safety-permissive` in the test code.
I ran the CK `smoke-builder` tests with the staging compiler to verify.
1f6768472e