Infrastructure: remove Squirrel code signing (Mudlet#7546)

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#### Brief overview of PR changes/additions
Remove Squirrel code signing
#### Motivation for adding to Mudlet
No longer in use as we now use Azure Trusted Signing
#### Other info (issues closed, discussion etc)

Co-authored-by: Vadim Peretokin <[email protected]>

CI/deploy-mudlet-for-windows.sh

@@ -270,9 +270,8 @@ else
   ./squirrel.windows/tools/Squirrel --releasify "$nupkg_path" \
     --releaseDir "$GITHUB_WORKSPACE/squirreloutput" \
     --loadingGif "$GITHUB_WORKSPACE/installers/windows/splash-installing-2x.png" \
-    --no-msi --setupIcon "$InstallerIconFile" \
-    -n "/a /f $GITHUB_WORKSPACE/installers/windows/code-signing-certificate.p12 /p $WIN_SIGNING_PASS /fd sha256 /tr http://timestamp.digicert.com /td sha256"
-
+    --no-msi --setupIcon "$InstallerIconFile" 
+
   echo "=== Removing old directory content of release folder ==="
   rm -rf "${PACKAGE_DIR:?}/*"