build: use private app instead of public bot in CI

See this [discussion](https://github.com/orgs/community/discussions/25305#discussioncomment-8256560) for more details.

.github/actions/bootstrap-environ/action.yml

@@ -10,7 +10,14 @@ inputs:
 runs:
   using: composite
   steps:
+  - uses: actions/create-github-app-token@v1
+    id: app-token
+    with:
+      app-id: ${{ vars.RELEASE_BOT_APP_ID }}
+      private-key: ${{ secrets.RELEASE_BOT_APP_PKEY }}
   - uses: actions/checkout@v4
+    with:
+      token: ${{ steps.app-token.outputs.token }}
   - uses: actions/setup-python@v5
     with:
       python-version: ${{ inputs.python-version }}

.github/workflows/docs.yml

@@ -5,10 +5,6 @@ on:
     branches: ["main"]
     tags: ["*"]
 
-env:
-  GIT_COMMITTER_NAME: "github-actions[bot]"
-  GIT_COMMITTER_EMAIL: "41898282+github-actions[bot]@users.noreply.github.com"
-
 defaults:
   run:
     shell: bash
@@ -31,10 +27,6 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
         runner: ${{ matrix.os }}
-    - name: Setup Git Credentials
-      run: |
-        git config --global user.email "41898282+github-actions[bot]@users.noreply.github.com"
-        git config --global user.name "github-actions[bot]"
     - name: Update the Changelog
       run: |
         make changelog

.github/workflows/tag.yml

@@ -19,10 +19,6 @@ defaults:
   run:
     shell: bash
 
-env:
-  GIT_COMMITTER_NAME: "github-actions[bot]"
-  GIT_COMMITTER_EMAIL: "41898282+github-actions[bot]@users.noreply.github.com"
-
 jobs:
   create-version:
     runs-on: ${{ matrix.os }}
@@ -38,10 +34,6 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
         runner: ${{ matrix.os }}
-    - name: Setup Git Credentials
-      run: |
-        git config --global user.email "41898282+github-actions[bot]@users.noreply.github.com"
-        git config --global user.name "github-actions[bot]"
     - name: Tag New Version
       run: make release-version rule=${{ inputs.level }}
     - name: Push New Version