release: fix signing in release workflow (#1649)

Fix the `dotnet tool install` command for code signing in the release
workflow.

D'oh!

Author: mjcheetham

.github/workflows/release.yml

@@ -351,7 +351,7 @@ jobs:
 
     - name: Install sign CLI tool
       run: |
-        dotnet tool install -g --version 0.9.1-beta.24325.5
+        dotnet tool install -g sign --version 0.9.1-beta.24325.5
 
     - name: Sign payload
       run: |
@@ -427,7 +427,7 @@ jobs:
 
     - name: Install sign CLI tool
       run: |
-        dotnet tool install -g --version 0.9.1-beta.24325.5
+        dotnet tool install -g sign --version 0.9.1-beta.24325.5
 
     - name: Sign package
       run: |