Use utf8NoBOM encoding when writing to GITHUB_ENV

Out-File -Encoding utf8 can emit a BOM on certain PowerShell
configurations which corrupts the first variable name. Switch to
utf8NoBOM to guarantee BOM-less output.

Author: MariusStorhaug

src/publish.ps1

@@ -105,8 +105,8 @@ LogGroup 'Resolve version from manifest' {
     } | Format-List | Out-String
 
     # Expose publish context to subsequent steps so the cleanup step can gate on release type.
-    "PSMODULE_PUBLISH_PSMODULE_CONTEXT_IsPrerelease=$($createPrerelease.ToString().ToLower())" | Out-File -Path $env:GITHUB_ENV -Append -Encoding utf8
-    "PSMODULE_PUBLISH_PSMODULE_CONTEXT_ReleaseTag=$releaseTag" | Out-File -Path $env:GITHUB_ENV -Append -Encoding utf8
+    "PSMODULE_PUBLISH_PSMODULE_CONTEXT_IsPrerelease=$($createPrerelease.ToString().ToLower())" | Out-File -Path $env:GITHUB_ENV -Append -Encoding utf8NoBOM
+    "PSMODULE_PUBLISH_PSMODULE_CONTEXT_ReleaseTag=$releaseTag" | Out-File -Path $env:GITHUB_ENV -Append -Encoding utf8NoBOM
 }
 #endregion Resolve version from manifest