Allow seamless sleet upgrades without requiring workflow updates

Author: kzu

.github/workflows/build.yml

@@ -84,7 +84,7 @@ jobs:
           SLEET_CONNECTION: ${{ secrets.SLEET_CONNECTION }}
         if: env.SLEET_CONNECTION != ''
         run: |
-          dotnet tool install -g --version 4.0.18 sleet 
+          dotnet tool update sleet -g --allow-downgrade --version $(curl -s --compressed ${{ vars.SLEET_FEED_URL }} | jq '.["sleet:version"]' -r)        
           sleet push bin --config none -f --verbose -p "SLEET_FEED_CONTAINER=nuget" -p "SLEET_FEED_CONNECTIONSTRING=${{ secrets.SLEET_CONNECTION }}" -p "SLEET_FEED_TYPE=azure" || echo "No packages found"
 
   dotnet-format:

.github/workflows/publish.yml

@@ -53,5 +53,5 @@ jobs:
           SLEET_CONNECTION: ${{ secrets.SLEET_CONNECTION }}
         if: env.SLEET_CONNECTION != ''
         run: |
-          dotnet tool install -g --version 4.0.18 sleet 
+          dotnet tool update sleet -g --allow-downgrade --version $(curl -s --compressed ${{ vars.SLEET_FEED_URL }} | jq '.["sleet:version"]' -r)        
           sleet push bin --config none -f --verbose -p "SLEET_FEED_CONTAINER=nuget" -p "SLEET_FEED_CONNECTIONSTRING=${{ secrets.SLEET_CONNECTION }}" -p "SLEET_FEED_TYPE=azure" || echo "No packages found"