Fix security issues, UB, and ARM CI build failure

- Added NULL check for malloc in instantiate().
- Clamped bits, gain_in, overflow, and dry_wet parameters in run().
- Fixed undefined behavior in handle_sample() by using double precision, clamping before casting to int64_t, and avoiding division by zero.
- Fixed ARM CI failure by patching plugin-torture: removed x86-specific flags and SSE intrinsics (xmmintrin.h) from build.
- Removed binary artifact quasar.o.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: kassoulet

Dockerfile

@@ -11,6 +11,8 @@ RUN apt-get install -y build-essential git pkg-config lv2-dev ladspa-sdk liblilv
 RUN git clone https://github.com/cth103/plugin-torture /plugin-torture
 WORKDIR /plugin-torture
 RUN sed -i 's/-msse -mfpmath=sse//g' Makefile
+RUN sed -i '/#include <xmmintrin.h>/d' src/main.cc
+RUN sed -i '172,175d' src/main.cc
 RUN make -j$(nproc)
 
 # Build lv2bm