Fix libzstd-dev on debian build

[EdgarModesto23]

From #1247

This patch fixes issues mentioned by @kiplingw on #1247 (comment).

The issue was caused because the patch that adds zstd support uses the ZSTD_defaultCLevel() function. which is only supported by libzstd v1.5.0+. The current configuration uses libzstd v1.4.8

This PR fixes that by specifying that pistache depends on libzstd >= 1.5.4.

[kiplingw]

Unfortunately that does not fix the problem as I previously alluded to. Version 1.4.8 is what ships with Jammy. Merging will continue to break all builds on Jammy. There are several options:

• Drop Pistache support entirely for Jammy;
• We continue supporting Jammy, but just don't build with ZSTD support on it;
• Check at configure time for the presence of ZSTD_defaultCLevel(), after verifying the library is present, and then define some preprocessor definition similar to how AC_CHECK_FUNC works;
• Rewrite your code so that, when building with ZSTD support, it does not use any interfaces introduced after 1.4.8.

I think the third option is the best engineering approach.

[kiplingw]

Please see my comments.

[EdgarModesto23]

@kiplingw Got it. I think in this case, option 4 is the easiest solution. Since ZSTD_defaultCLevel() just returns the default for ZSTD_CLEVEL_DEFAULT, which is 3 according to documentation.

[kiplingw]

In that case then I'll close this PR and you can amend #1247.