fix: support Xcelium SCC installed-package flow

[valtterikarmitsa]

This fixes the SCC installed-package flow for Xcelium/NCSC builds.

Changes:

• use the NCSC-compatible TLM extension cache insertion form only for NCSC builds, while preserving the existing OSCI/default path.
• generate the installed SCC package dependency on the configured SystemC provider, so Xcelium builds re-find XMSystemC instead of SystemCLanguage.
• re-find optional public compression dependencies from the installed package config when they are linked into exported targets.
• add a minimal --deps_only mode to install_wo_conan.sh so third-party dependencies can be built separately from SystemC/SCC and reused by a direct CMake SCC build.

[eyck]

LGTM