Target a specific VS build tools channel

The channel we used before was "Current", meaning any update to it, was
also used locally. This caused an issue where the build tools
misbehaved, and were not able to identify the compiler.

jenkins/windows/Dockerfile

@@ -19,15 +19,19 @@ RUN powershell `
       -Command "(New-Object System.Net.WebClient).DownloadFile('https://aka.ms/vscollect.exe', 'C:\TEMP\collect.exe')"
 
 # Download channel for fixed install.
-ARG CHANNEL_URL=https://aka.ms/vs/17/release/channel
+# This targets a specific version, since the global current channel version is updated regularly.
+# Which can lead to an incompatibility issue in the builds. Now we target an LTSC channel for stability.
+ARG CHANNEL_URL=https://aka.ms/vs/17/release.ltsc.17.6/channel
 RUN powershell `
       -NoProfile `
       -ExecutionPolicy Bypass `
       -Command "(New-Object System.Net.WebClient).DownloadFile(\"$env:CHANNEL_URL\", 'C:\TEMP\VisualStudio.chman')"
 
 # Download and install Build Tools for Visual Studio 2022 for native desktop workload,
-# including 14.1 (VS 2017) and 14.2 (VS 2019) components
-ARG BUILDTOOLS_URL=https://aka.ms/vs/17/release/vs_buildtools.exe
+# including 14.1 (VS 2017) and 14.2 (VS 2019) components.
+# This targets a specific version, since the global current channel version is updated regularly.
+# Which can lead to an incompatibility issue in the builds. Now we target an LTSC channel for stability.
+ARG BUILDTOOLS_URL=https://aka.ms/vs/17/release.ltsc.17.6/vs_buildtools.exe
 RUN powershell `
     -NoProfile `
     -ExecutionPolicy Bypass `