Prefer poetry sync to poetry install --sync

Use `poetry sync` instead of `poetry install --sync`, since the latter
is deprecated and will be removed after June 2025, as seen in the
following warning message:

  The `--sync` option is deprecated and slated for removal in the next
  minor release after June 2025, use the `poetry sync` command instead.

RELEASE.md

@@ -141,7 +141,7 @@ Here is what you need to do:
   poetry env remove --all
 
   # Install the dependencies
-  poetry install --sync
+  poetry sync
   ```
 
 - [ ] Build the container image and the OCR language data
@@ -223,7 +223,7 @@ The Windows release is performed in a Windows 11 virtual machine (as opposed to
   poetry env remove --all
 
   # Install the dependencies
-  poetry install --sync
+  poetry sync
   ```
 
 - [ ] Copy the container image into the VM

dev_scripts/qa.py

@@ -836,7 +836,7 @@ class QAWindows(QABase):
     )
     def install_poetry(self):
         self.run("python", "-m", "pip", "install", "poetry", "poetry-plugin-export")
-        self.run("poetry", "install", "--sync")
+        self.run("poetry", "sync")
 
     @QABase.task("Build Dangerzone container image", ref=REF_BUILD, auto=True)
     def build_image(self):

dodo.py

@@ -206,7 +206,7 @@ def task_build_image():
 
 def task_poetry_install():
     """Setup the Poetry environment"""
-    return {"actions": ["poetry install --sync"], "clean": ["poetry env remove --all"]}
+    return {"actions": ["poetry sync"], "clean": ["poetry env remove --all"]}
 
 
 def task_macos_build_dmg():