chore(ci): cleanup copilot instructions - 2 (#5548)

Use correct file names for Copilot instructions

.claude/rules/code-review.md

@@ -1 +1 @@
-../../.github/instructions/code-review.copilot-instructions.md
+../../.github/instructions/code-review.instructions.md

.claude/rules/go-dev.md

@@ -1 +1 @@
-../../.github/instructions/go-dev.copilot-instructions.md
+../../.github/instructions/go-dev.instructions.md

.claude/rules/go-style.md

@@ -0,0 +1 @@
+../../.github/instructions/go-style.instructions.md

.claude/rules/go-testing.md

@@ -1 +1 @@
-../../.github/instructions/go-testing.copilot-instructions.md
+../../.github/instructions/go-testing.instructions.md

.claude/rules/go.md

@@ -1 +0,0 @@
-../../.github/instructions/go.copilot-instructions.md