bump agent version to v3.94.0

Bump agent version to v3.94.0

Author: PriyaSudip

packer/windows/scripts/install-buildkite-agent.ps1

@@ -1,7 +1,7 @@
 # Stop script execution when a non-terminating error occurs
 $ErrorActionPreference = "Stop"
 
-$AGENT_VERSION = "3.93.1"
+$AGENT_VERSION = "3.94.0"
 
 Write-Output "Creating bin dir..."
 New-Item -ItemType directory -Path C:\buildkite-agent\bin