Bump powershell (#14)

Bumps powershell from 7.1.3-alpine-3.12-20210802 to 7.1.3-alpine-3.12-20210803.

---
updated-dependencies:
- dependency-name: powershell
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Dockerfile

@@ -3,7 +3,7 @@
 
 ARG MODULE_VERSION=0.9.0
 
-FROM mcr.microsoft.com/powershell:7.1.3-alpine-3.12-20210802
+FROM mcr.microsoft.com/powershell:7.1.3-alpine-3.12-20210803
 SHELL ["pwsh", "-Command"]
 RUN $ProgressPreference = [System.Management.Automation.ActionPreference]::SilentlyContinue; \
     $Null = New-Item -Path /ps_modules/ -ItemType Directory -Force; \