- Gcc11 has raised the bar on strict aliasing requirements even
further. This has given rise to seemingly senseless warnings
like:
ncx.c: In function 'ncx_putn_float_double':
ncx.c:272:20: warning: 'xx' may be used uninitialized [-Wmaybe-uninitialized]
272 | uint32_t tmp = *(uint32_t*)src;
| ^~~~~~~~~~~~~~~
ncx.c:3562:14: note: 'xx' was declared here
3562 | ix_float xx = NC_FILL_FLOAT;
| ^~
but what is worse, data in netcdf files is missing. Luckily, this
was caught by the test suite.
These warnings and further type punning warnings should be fixed
eventually. However, for now, lets cry defeat, disable strict
aliasing and get netcdf back working again.

- Add build support for gcc11 to HPC build.
- Update to version 4.7.4.
* Enhancements:
- Bump the NC_DISPATCH_VERSION from 2 to 3
- Better cross platform path name management. This converts paths for
various platforms (e.g. Windows, MSYS, etc.) so that they are in
the proper format for the executing platform. See Github #1958.
- Add support for storing NCZarr data in zip files. See Github #1908.
- Optimizations to NCZarr, cleanup of code cruft, NCZarr test cases,
performance test to NCZarr. See Github #1942.
- Provide .rc fields for S3 authentication: HTTP.S3.ACCESSID and
HTTP.S3.SECRETKEY.
- Give the client control over what parts of a DAP2 URL are URL
encoded (i.e. xx). This is to support the different decoding (forwarded request 904468 from eeich)