Add error handling for exit code of Chocolatey

Powershell does not automatically exit a script when an `.exe` returns a
non-successful exit code. This is due to a lack of exit code
standardisation across programs for the Windows platform. Therefore we
need to check for the particular exit code of an `.exe` in order to
report it to the github actions platform. Note that exit codes from
`.exe` invocations are placed in `$LastExitCode` and exit codes from
Powershell cmdlets such as `Write-Output` are placed in the separate
`$?` variable.

Author: thomasspriggs

.github/workflows/pull-request-checks.yaml

@@ -611,6 +611,11 @@ jobs:
       - name: Fetch dependencies
         run: |
           choco install winflexbison3
+          if($LastExitCode -ne 0)
+          {
+            Write-Output "::error ::Dependency installation via Chocolatey failed."
+            exit $LastExitCode
+          }
           nuget install clcache -OutputDirectory "c:\tools" -ExcludeVersion -Version 4.1.0
           echo "c:\tools\clcache\clcache-4.1.0" >> $env:GITHUB_PATH
           Invoke-WebRequest -Uri https://github.com/Z3Prover/z3/releases/download/z3-4.8.10/z3-4.8.10-x64-win.zip -OutFile .\z3.zip
@@ -664,6 +669,11 @@ jobs:
       - name: Fetch dependencies
         run: |
           choco install -y winflexbison3 strawberryperl wget
+          if($LastExitCode -ne 0)
+          {
+            Write-Output "::error ::Dependency installation via Chocolatey failed."
+            exit $LastExitCode
+          }
           nuget install clcache -OutputDirectory "c:\tools" -ExcludeVersion -Version 4.1.0
           echo "c:\tools\clcache\clcache-4.1.0" >> $env:GITHUB_PATH
           echo "c:\ProgramData\chocolatey\bin" >> $env:GITHUB_PATH
@@ -731,6 +741,11 @@ jobs:
       - name: Fetch dependencies
         run: |
           choco install winflexbison3
+          if($LastExitCode -ne 0)
+          {
+            Write-Output "::error ::Dependency installation via Chocolatey failed."
+            exit $LastExitCode
+          }
           nuget install clcache -OutputDirectory "c:\tools" -ExcludeVersion -Version 4.1.0
           echo "c:\tools\clcache\clcache-4.1.0" >> $env:GITHUB_PATH
       - name: Setup Visual Studio environment