build: cmake: require {fmt} >= 9.0.0

we are using `fmt::ostream_formatter` which was introduced in
{fmt} v9.0.0, see https://github.com/fmtlib/fmt/releases/tag/9.0.0 .

before this change, we depend on Seastar to find {fmt}. but
the minimal version of {fmt} required by Seastar is 5.0.0, which
cannot fulfill the needs to build scylladb.

in this change, we find {fmt} package in scylla, and specify the
minimal required version of 9.0.0, so the build can fail at the
configuration time. {fmt} v8 could be still being used by users.
for instance, ubuntu:jammy comes with libfmt-dev 8.1.1. and
ubuntu:jammy is EOL in Apr 2027, see
https://ubuntu.com/about/release-cycle .

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18386

CMakeLists.txt

@@ -67,6 +67,7 @@ find_package(Lua REQUIRED)
 find_package(ZLIB REQUIRED)
 find_package(ICU COMPONENTS uc i18n REQUIRED)
 find_package(absl COMPONENTS hash raw_hash_set REQUIRED)
+find_package(fmt 9.0.0 REQUIRED)
 find_package(libdeflate REQUIRED)
 find_package(libxcrypt REQUIRED)
 find_package(Snappy REQUIRED)