Remove PR/issue closing instructions from coding agent prompts

The Copilot coding agent cannot close PRs or issues. Instead, instruct
it to push an empty commit explaining the no-changes outcome, and let
the maintainer handle cleanup manually.

Author: brunoborges

.github/prompts/agentic-merge-upstream.prompt.md

@@ -333,12 +333,7 @@ Run the finish script which updates `.lastmerge`, runs a final build, and pushes
 gh pr edit --add-label "upstream-sync"
 ```
 
-> **No-changes scenario (coding agent only):** If after analyzing the upstream diff there are no relevant changes to port to the Java SDK, you **MUST** close the auto-created pull request and the triggering issue by running these commands in a terminal:
->
-> 1. Close the PR: `gh pr close $(gh pr view --json number --jq .number) --comment "No relevant upstream changes to port to the Java SDK."`
-> 2. Close the issue: `gh issue close ISSUE_NUMBER --reason "not planned" --comment "No relevant upstream changes to port to the Java SDK. Closing as not planned."` (replace ISSUE_NUMBER with the actual issue number)
->
-> **CRITICAL: You MUST run these `gh` CLI commands in a terminal. Do NOT skip these steps.** Both commands are required when there are no changes to port.
+> **No-changes scenario (coding agent only):** If after analyzing the upstream diff there are no relevant changes to port to the Java SDK, push an empty commit with a message explaining why no changes were needed, so the PR reflects the analysis outcome. The repository maintainer will close the PR and issue manually.
 
 **If running manually** (e.g., from VS Code via the reusable prompt), create the Pull Request using `gh` CLI or the GitHub MCP tool. Then add the label:
 

.github/prompts/coding-agent-merge-instructions.md

@@ -15,15 +15,5 @@ Add the 'upstream-sync' label to the existing PR by running this command in a te
     gh pr edit --add-label "upstream-sync"
 
 If after analyzing the upstream diff there are no relevant changes to port to the Java SDK,
-you MUST close the pull request and the issue. Run the following commands in a terminal:
-
-1. Close the auto-created pull request:
-
-    gh pr close $(gh pr view --json number --jq .number) --comment "No relevant upstream changes to port to the Java SDK."
-
-2. Close the triggering issue as 'not planned' (replace ISSUE_NUMBER with the actual issue number from the issue that was assigned to you):
-
-    gh issue close ISSUE_NUMBER --reason "not planned" --comment "No relevant upstream changes to port to the Java SDK. Closing as not planned."
-
-CRITICAL: You MUST run these gh CLI commands in a terminal. Do NOT skip these steps.
-Both the PR close and issue close commands are required when there are no changes to port.
+push an empty commit with a message explaining why no changes were needed, so the PR reflects
+the analysis outcome. The repository maintainer will close the PR and issue manually.