Change set env variable to run with powershell

.circleci/config.yml

@@ -43,6 +43,7 @@ jobs:
             certutil -decode "speckle-sharp-ci-tools\SignTool\AEC Systems Ltd.txt" "speckle-sharp-ci-tools\SignTool\AEC Systems Ltd.pfx"
       - run:
           name: Set Environment Variable
+          shell: powershell.exe
           command: |
             $tag = if([string]::IsNullOrEmpty($env:CIRCLE_TAG)) { "2.0.999" } else { $env:CIRCLE_TAG }
             $semver = if($tag.Contains('/')) {$tag.Split("/")[0] } else { $tag }
@@ -51,11 +52,6 @@ jobs:
             python patch_version.py $semver
           environment:
             WORKFLOW_NUM: << pipeline.number >>
-      - run:
-          name: Create Innosetup signing cert
-          command: |
-            echo $env:PFX_B64 > "speckle-sharp-ci-tools\SignTool\AEC Systems Ltd.txt"
-            certutil -decode "speckle-sharp-ci-tools\SignTool\AEC Systems Ltd.txt" "speckle-sharp-ci-tools\SignTool\AEC Systems Ltd.pfx"
       - run:
           name: Build Installer
           command: speckle-sharp-ci-tools\InnoSetup\ISCC.exe speckle-sharp-ci-tools\sketchup.iss /Sbyparam=$p