Resolve NVHPC testing issues when compiling with -O1 and higher and -DNDEBUG

**Describe the bug**
When compiling HDF5 with NVHPC versions 23.5 - 23.9 (additional versions may also be applicable) and with `-O1` (or higher) and `-DNDEBUG`, testing failures occur in the following tests:

- H5PLUGIN-filter_plugin - `incorrect metadata checksum after all read attempts`
- H5TEST-flush2 - `Segmentation fault` during `Testing H5Fflush (part2 with flush + SWMR)`
- H5TEST-testhdf5-base - Many instances of `incorrect metadata checksum after all read attempts` during `Testing -- Attributes (attr)`
- MPI_TEST_t_filters_parallel - `malloc(): invalid next size (unsorted)` after `Testing fill time H5D_FILL_TIME_NEVER`

Compiling without `-DNDEBUG` appears to pass testing, but is not ideal due to compiling in asserts and other library debug code. Since these tests pass with an optimization level of `-O1` (and `-O0`) and it is currently unclear whether the test failures are due to issues in HDF5 or issues in the 'nvc' compiler, the maximum optimization level for NVHPC has been set to `-O1` until the test failures can be resolved.

Note that even at `-O1` optimization level, there still appears to be a sporadic test failure in the Java JUnit tests that has occasionally been seen in `JUnit-TestH5Pfapl` and `JUnit-TestH5D`. It is also unclear whether this is an issue in HDF5 or with the 'nvc' compiler. Testing of Java has been disabled in the NVHPC GitHub actions for now.

Note also that NVHPC version 23.9 will fail to compile the test file `test/tselect.c` with a `use of undefined value` compiler error when the optimization level used is `-O2` or higher. Nvidia is aware of this issue and has suggested lowering the optimization level to `-O1` for the time being: https://forums.developer.nvidia.com/t/hdf5-no-longer-compiles-with-nv-23-9/269045.

**Expected behavior**
HDF5 tests should pass with the NVHPC compiler collection at any optimization level.

**Platform (please complete the following information)**
- HDF5 version - develop ([562c53c44a22c979419deb1cb025b2a74900fbac](https://github.com/HDFGroup/hdf5/commit/562c53c44a22c979419deb1cb025b2a74900fbac))
- OS and version - ubuntu-latest (NVHPC GitHub action)
- Compiler and version - NVHPC (nvc) 23.5 - 23.9
- Build system (e.g. CMake, Autotools) and version - CMake and Autotools
- Any configure options you specified - Refer to [nvhpc-cmake.yml](https://github.com/HDFGroup/hdf5/blob/develop/.github/workflows/nvhpc-cmake.yml) / [nvhpc-auto.yml](https://github.com/HDFGroup/hdf5/blob/develop/.github/workflows/nvhpc-auto.yml)
- MPI library and version (parallel HDF5) - OpenMPI included in NVHPC