Revert "Fix Python emitter CI publish failure: stamp prerelease version in Build-Packages.ps1" (#10881)

Reverts #10817

After discussion, we revert this PR to avoid duplicated alpha release
for same python emitter content.

Author: msyyc

packages/http-client-python/eng/scripts/Build-Packages.ps1

@@ -75,13 +75,6 @@ New-Item -ItemType Directory -Force -Path "$outputPath/packages" | Out-Null
 $emitterVersion = node -p -e "require('$packageRoot/package.json').version"
 Write-Host "Package version: $emitterVersion"
 
-# Stamp prerelease version if BuildNumber is provided
-if ($BuildNumber) {
-    $versionTag = $Prerelease ? "-alpha" : "-beta"
-    $emitterVersion = "$emitterVersion$versionTag.$BuildNumber"
-    Write-Host "Stamped prerelease version: $emitterVersion"
-}
-
 Push-Location "$packageRoot"
 try {
     # Step 1: Build the emitter and generator
@@ -94,20 +87,12 @@ try {
         Invoke-LoggedCommand "npm run lint" -GroupOutput
     }
 
-    # Step 3: Stamp version in package.json if prerelease
-    if ($BuildNumber) {
-        Write-Host "`n=== Updating package.json version to $emitterVersion ===" -ForegroundColor Cyan
-        $packageJson = Get-Content -Raw "package.json" | ConvertFrom-Json -AsHashtable
-        $packageJson.version = $emitterVersion
-        $packageJson | ConvertTo-Json -Depth 100 | Out-File -Path "package.json" -Encoding utf8 -NoNewline -Force
-    }
-
-    # Step 4: Create npm package
+    # Step 3: Create npm package
     Write-Host "`n=== Creating npm package ===" -ForegroundColor Cyan
     Invoke-LoggedCommand "npm pack"
     Copy-Item "typespec-http-client-python-$emitterVersion.tgz" -Destination "$outputPath/packages"
 
-    # Step 5: Verify package can be installed
+    # Step 4: Verify package can be installed
     Write-Host "`n=== Verifying package installation ===" -ForegroundColor Cyan
     Invoke-LoggedCommand "npm install typespec-http-client-python-$emitterVersion.tgz" -GroupOutput