Dynamically link to conda-installed libspdlog

[jdblischak]

We want the conda libtiledbsoma binary to dynamically link to the conda-installed libspdlog.

• Problem originally identified in add tiledbsoma conda-forge/staged-recipes#28828
• Work upstream being tracked in [c++] Support dynamic linking to libspdlog single-cell-data/TileDB-SOMA#3585

conda-build should report that libspdlog was "Needed" just like it does for libfmt, which indicates it was successfully linked to the conda binary.

   INFO (libtiledbsoma,lib/libtiledbsoma.so): Needed DSO lib/libfmt.so.11 found in conda-forge/linux-64::fmt==11.0.2=h434a139_0
WARNING (libtiledbsoma): run-exports library package conda-forge/linux-64::spdlog==1.15.0=h10c9db5_0 in requirements/run but it is not used (i.e. it is overdepending or perhaps statically linked? If that is what you want then add it to `build/ignore_run_exports`)