fix CI: VS2026 runner image on Windows; non-PIC ncurses in aarch64 libfaust

- The windows-2025 image now carries Visual Studio 2026 alongside 2022, so
  CMake generates VS2026 solutions and the newest MSBuild was selected.
  Build libsamplerate with generator-agnostic `cmake --build`, and pin
  setup-msbuild to VS2022's MSBuild since the Projucer-generated projects
  use the v143 toolset.
- libfaust-ubuntu-aarch64.zip bundles a distro-built (non-PIC) ncurses
  inside libfaustwithllvm.a, which fails to link into dawdreamer.so with
  "relocation R_AARCH64_ADR_PREL_PG_HI21 ... can not be used when making a
  shared object". Add strip_nonpic_ncurses.py, which detects members having
  such relocations against external symbols (everything else in the archive
  only references __dso_handle, which binds locally) and deletes them; the
  terminfo symbols then resolve from the system libtinfo that the Makefile
  already links. download_libfaust.py runs it automatically for aarch64.
  Verified against the 2.85.9 release archive: exactly the 90 bundled
  ncurses objects are removed and the operation is idempotent.