Switch to pyside6 (#11)

* Switch to pyside6

* Remove class instatiation

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

environment.yml

@@ -3,7 +3,7 @@ channels:
   - conda-forge
 dependencies:
   - python>=3.10
-  - pyqt == 5.*
+  - pyside6
   - qtpy
   - scipy
   - numpy
@@ -15,7 +15,7 @@ dependencies:
   - libarchive
   - anaconda-client
   - boa
-  - conda-build < 4  # conda-build 24.x has a bug, missing update_index from conda_build.index
+  - conda-build # < 4  # conda-build 24.x has a bug, missing update_index from conda_build.index
   - conda-verify
   - python-build
   - twine  # for uploading to pypi and testpypi

src/hyspecppt/hyspecppt.py

@@ -16,14 +16,6 @@
 class HyspecPPT(QMainWindow):
     """Main Package window"""
 
-    __instance = None
-
-    def __new__(cls):
-        """Create new instance of the HyspecPPT"""
-        if not cls.__instance:
-            cls.__instance = super(HyspecPPT, cls).__new__(cls)
-        return cls.__instance
-
     def __init__(self, parent=None):
         """Constructor"""
         super().__init__(parent)