merge: combine v9 upgrade (PR #708) with createOctokit feature

Merges the @actions/github v9 upgrade branch into the createOctokit
feature branch, combining ADR steps 1 and 3 into a single major release.

Changes from v9 upgrade:
- @actions/github 6.x → 9.0.0 (ESM-only)
- @octokit/core v5→v7, plugin-request-log v4→v6, plugin-retry v6→v8
- tsconfig: moduleResolution bundler, module/target es2022
- ts-jest: module commonjs override for CJS test execution
- License file updates for new dependency versions

Conflict resolutions:
- src/async-function.ts: v9 import style + createOctokit type
- types/async-function.d.ts: aligned with .ts file
- integration.yml: v9 UA checks + createOctokit test job
- dist/index.js: rebuilt via ncc

Additional fix:
- getoctokit-integration.test.ts: use mock instead of direct
  @actions/github import (ESM-only v9 incompatible with Jest CJS)

All 32 tests passing, TypeScript clean, lint clean.

Author: salmanmkc

.github/workflows/integration.yml

@@ -154,28 +154,24 @@ jobs:
             return endpoint({}).headers['user-agent']
           result-encoding: string
       - run: |
-          matches_user_agent() {
-            local actual="$1"
-            local prefix="$2"
-            [[ "$actual" =~ ^${prefix}(\ actions_orchestration_id/[^[:space:]]+)?\ octokit-core\.js/ ]]
-          }
-
+          # User-agent format: <prefix> [actions_orchestration_id/<id>] octokit-core.js/<version> ...
+          # When ACTIONS_ORCHESTRATION_ID is set, the orchestration ID is inserted after the prefix
           echo "- Validating user-agent default"
-          expected="actions/github-script"
-          if ! matches_user_agent "${{steps.user-agent-default.outputs.result}}" "$expected"; then
-            echo $'::error::\u274C' "Expected user-agent to start with '$expected' and include 'octokit-core.js/', got ${{steps.user-agent-default.outputs.result}}"
+          ua="${{steps.user-agent-default.outputs.result}}"
+          if [[ "$ua" != "actions/github-script"* ]] || [[ "$ua" != *"octokit-core.js/"* ]]; then
+            echo $'::error::\u274C' "Expected user-agent to start with 'actions/github-script' and contain 'octokit-core.js/', got $ua"
             exit 1
           fi
           echo "- Validating user-agent set to a value"
-          expected="foobar"
-          if ! matches_user_agent "${{steps.user-agent-set.outputs.result}}" "$expected"; then
-            echo $'::error::\u274C' "Expected user-agent to start with '$expected' and include 'octokit-core.js/', got ${{steps.user-agent-set.outputs.result}}"
+          ua="${{steps.user-agent-set.outputs.result}}"
+          if [[ "$ua" != "foobar"* ]] || [[ "$ua" != *"octokit-core.js/"* ]]; then
+            echo $'::error::\u274C' "Expected user-agent to start with 'foobar' and contain 'octokit-core.js/', got $ua"
             exit 1
           fi
           echo "- Validating user-agent set to an empty string"
-          expected="actions/github-script"
-          if ! matches_user_agent "${{steps.user-agent-empty.outputs.result}}" "$expected"; then
-            echo $'::error::\u274C' "Expected user-agent to start with '$expected' and include 'octokit-core.js/', got ${{steps.user-agent-empty.outputs.result}}"
+          ua="${{steps.user-agent-empty.outputs.result}}"
+          if [[ "$ua" != "actions/github-script"* ]] || [[ "$ua" != *"octokit-core.js/"* ]]; then
+            echo $'::error::\u274C' "Expected user-agent to start with 'actions/github-script' and contain 'octokit-core.js/', got $ua"
             exit 1
           fi
           echo $'\u2705 Test passed' | tee -a $GITHUB_STEP_SUMMARY