fix: install pip requirements from requirements.txt. (#331)

* fix: install pip requirements from requirements.txt.

* chore: add requirements.txt to def file.

ci/singularity/ubuntu20.04.def

@@ -1,16 +1,22 @@
 Bootstrap: library
 From: ubuntu:20.04
 
+%files
+
+    ./requirements.txt requirements.txt
+
 %post
     apt-get update
     apt-get install python3.8 python3-distutils curl build-essential libx11-xcb-dev libglu1-mesa-dev libxkbcommon0 libglx0 libfontconfig libglib2.0-0 libdbus-1-3 libxcb-xinerama0 libxkbcommon-x11-0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-render-util0 libxcb-shape0 libgfortran5 -y && rm -rf /var/lib/apt/lists/*
     curl https://bootstrap.pypa.io/get-pip.py | python3.8
-    python3.8 -m pip install PySide6==6.2.0 chardet
+    python3.8 -m pip install -r requirements.txt
+    rm requirements.txt
     cd /usr/local/lib/python3.8/dist-packages/PySide6
     ls | grep .so | grep -v -e "QtCore.*" -e "QtGui.*" -e "QtCharts.*" -e "QtWidgets.*" -e "libpyside6" -e "libshiboken6" -e "QtUiTools" | xargs rm
     cd
     python3.8 -m pip uninstall pip -y
     apt-get remove curl -y
+
 
 %help