chore: add entry in nls for %github.copilot.config.claudeSonnet45AlternatePrompt% (#1219)

Author: ulugbekna

package.nls.json

@@ -141,6 +141,7 @@
 	"github.copilot.config.gpt5AlternatePrompt": "Specifies an experimental alternate prompt to use for GPT-5 models.",
 	"github.copilot.config.gpt5CodexAlternatePrompt": "Specifies an experimental alternate prompt to use for the GPT-5-Codex model.",
 	"github.copilot.config.grokCodeAlternatePrompt": "Specifies an experimental alternate prompt to use for Grok Code models.",
+	"github.copilot.config.claudeSonnet45AlternatePrompt": "Specifies an experimental alternate prompt to use for Claude Sonnet 4.5.",
 	"github.copilot.command.fixTestFailure": "Fix Test Failure",
 	"copilot.description": "Ask or edit in context",
 	"copilot.edits.description": "Edit files in your workspace",