Bump to OpenJPH 0.21.0

[palemieux]

Replace my OpenJPH feature branch with OpenJPH 0.21.0

[cary-ilm]

@palemieux and/or @peterhillman, any idea why the fuzzing workflow fails? It appears to be failing to link with undefined references to openjph and add odd error just before:

/usr/bin/ld: /usr/bin/ld: DWARF error: invalid or unhandled FORM value: 0x25

Does the fuzzer link line need to be updated?

Now that I think about, I believe this workflow was failing on the PR prior to merge, but I assumed it was because of other issues.

Also, @peterhillman, do we need to update something to get the fuzzer to run on the htj2k-beta branch? Presumably, it should.

[palemieux]

The OpenJPH library might be missing from the oss-fuzz build file for OpenEXR at https://github.com/google/oss-fuzz/blob/bfa03c999c5bc5e69e28d656531a8f5705eb2730/projects/openexr/build.sh#L24 ?

Who has been handling oss-fuzz within the OpenEXR community. I can work with them to fix oss-fuzz.

[cary-ilm]

We'll resolve the fuzz failure separately, unrelated to this.