Specify version when installing WiX

Update our CI job and build instructions with the latest WiX version, so
that we don't encounter any installation issues when new WiX versions
are released.

Also, add a reminder in our release instruction to bump the WiX version
before we start a new release.

Fixes #1087

.github/workflows/ci.yml

@@ -125,9 +125,9 @@ jobs:
         with:
           dotnet-version: "8.x"
       - name: Install WiX Toolset
-        run: dotnet tool install --global wix
+        run: dotnet tool install --global wix --version 5.0.2
       - name: Add WiX UI extension
-        run: wix extension add --global WixToolset.UI.wixext
+        run: wix extension add --global WixToolset.UI.wixext/5.0.2
       - name: Build the MSI installer
         # NOTE: This also builds the .exe internally.
         run: poetry run .\install\windows\build-app.bat

BUILD.md

@@ -478,13 +478,13 @@ poetry shell
 Install [.NET SDK](https://dotnet.microsoft.com/en-us/download) version 6 or later. Then, open a terminal and install the latest version of [WiX Toolset .NET tool](https://wixtoolset.org/) **v5** with:
 
 ```sh
-dotnet tool install --global wix --version 5.*
+dotnet tool install --global wix --version 5.0.2
 ```
 
 Install the WiX UI extension. You may need to open a new terminal in order to use the newly installed `wix` .NET tool:
 
 ```sh
-wix extension add --global WixToolset.UI.wixext/5.x.y
+wix extension add --global WixToolset.UI.wixext/5.0.2
 ```
 
 > [!IMPORTANT]

RELEASE.md

@@ -10,6 +10,7 @@ Here is a list of tasks that should be done before issuing the release:
       You can generate its content with the the `poetry run ./dev_scripts/generate-release-tasks.py` command.
 - [ ] [Add new Linux platforms and remove obsolete ones](https://github.com/freedomofpress/dangerzone/blob/main/RELEASE.md#add-new-linux-platforms-and-remove-obsolete-ones)
 - [ ] Bump the Python dependencies using `poetry lock`
+- [ ] Check for new [WiX releases](https://github.com/wixtoolset/wix/releases)
 - [ ] Update `version` in `pyproject.toml`
 - [ ] Update `share/version.txt`
 - [ ] Update the "Version" field in `install/linux/dangerzone.spec`