Add PR diff checker Github Action adopted from existing action

Author: nifadyev

{{cookiecutter.project_name}}/.github/actions/large-pr-check/action.yaml

@@ -0,0 +1,49 @@
+name: "Large PR checker"
+description: "Blocks PR if number of lines changed is excessive. Modified version of https://github.com/adolfosilva/gh-large-pr-check/blob/main/action.yml"
+
+inputs:
+  max_lines_changed:
+    description: "Maximum number of lines changed allowed"
+    required: true
+    default: "500"
+  target_branch:
+    description: The branch to compare against
+    required: true
+    default: main
+outputs:
+  total_lines_changed:
+    description: "Total lines changed in this PR"
+    value: ${{ steps.get_total_lines_changed.outputs.total_lines_changed }}
+
+runs:
+  using: "composite"
+  steps:
+    - id: fetch_target_branch
+      run: |
+        git fetch origin ${{ inputs.target_branch }}
+      shell: bash
+    - id: get_total_lines_changed
+      run: |
+        size=$(git diff --shortstat origin/${{ inputs.target_branch }} ':(exclude)*.lock' \
+        | awk '{ print $4+$6 }' \
+        | awk -F- '{print $NF}' \
+        | bc)
+
+        echo ""
+        echo "Total lines changed (note: *.lock files are excluded from this count): $size"
+        echo "total_lines_changed=$size" >> $GITHUB_OUTPUT
+      shell: bash
+    - name: Comment PR
+      if: ${{ fromJSON(steps.get_total_lines_changed.outputs.total_lines_changed) > fromJSON(inputs.max_lines_changed) }}
+      uses: thollander/actions-comment-pull-request@v2
+      with:
+        comment_tag: pr_size
+        mode: recreate
+        message: |
+          :boom: :boom: :boom:
+          Total lines changed ${{ steps.get_total_lines_changed.outputs.total_lines_changed }} is greater than ${{ inputs.max_lines_changed }}.
+          Please consider breaking this PR down.
+    - id: fail
+      if: ${{ fromJSON(steps.get_total_lines_changed.outputs.total_lines_changed) > fromJSON(inputs.max_lines_changed) }}
+      run: exit 1
+      shell: bash

{{cookiecutter.project_name}}/.github/workflows/pr.yaml

@@ -0,0 +1,21 @@
+name: Validate & Lint & Test
+
+on: [pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check-pr-diff:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check PR diff size
+        uses: ./.github/actions/large-pr-check
+        with:
+          target_branch: ${{ github.event.pull_request.base.ref }}
+          max_lines_changed: 100