Add Precommit and flake8 (#3287)

### What I did
add precommit and flake8 to prevent syntax warning in python, e.g. sonic-net/sonic-buildimage#18401
#### How I did it
- initially, this check will be optional to verify its functionality, allowing developers to proceed even if it fails.
- if it performs as expected, this check will become mandatory in the future.
- use flake8 v4.0.1 in order to use diff only for PRs (flake8 with diff only is deprecated in v6.0.0 PyCQA/flake8#1749
#### How to verify it
https://dev.azure.com/mssonic/build/_build/results?buildId=530004&view=logs&jobId=0cb31af1-9c12-5e3c-148e-856fdcff3a02

Author: maipbui

.azure-pipelines/pre-commit-check.yml

@@ -0,0 +1,35 @@
+steps:
+- checkout: self
+  clean: true
+  displayName: 'checkout sonic-utilities repo'
+
+- script: |
+    set -x
+    sudo pip install pre-commit
+    pre-commit install-hooks
+  displayName: 'Prepare pre-commit check'
+
+- script: |
+    # Run pre-commit check and capture the output
+    out=`pre-commit run --color never --from-ref HEAD^ --to-ref HEAD 2>&1`
+    RC=$?
+    if [[ $RC -ne 0 ]]; then
+      echo -e "The [pre-commit](http://pre-commit.com/) check detected issues in the files touched by this pull request.\n\
+    The pre-commit check is a mandatory check, please fix detected issues.\n\
+    \n\
+    To run the pre-commit checks locally, you can follow below steps:\n\
+      1. Ensure that default python is python3.\n\
+      2. Ensure that the 'pre-commit' package is installed:\n\
+         sudo pip install pre-commit\n\
+      3. Go to repository root folder\n\
+      4. Install the pre-commit hooks:\n\
+         pre-commit install\n\
+      5. Use pre-commit to check staged file:\n\
+         pre-commit\n\
+      6. Alternatively, you can check committed files using:\n\
+         pre-commit run --from-ref <commit_id> --to-ref <commit_id>\n"
+    fi
+    echo "Pre-commit check results:"
+    echo "$out"
+    exit $RC
+  displayName: 'Run pre-commit check'

.pre-commit-config.yaml

@@ -0,0 +1,9 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+-   repo: https://github.com/PyCQA/flake8
+    rev: 4.0.1
+    hooks:
+    -   id: flake8
+        entry: bash -c 'git diff HEAD^ HEAD -U0 -- "$@" | flake8 --diff "$@"' --
+        args: ["--max-line-length=120"]

azure-pipelines.yml

@@ -21,6 +21,16 @@ variables:
       value: $(Build.SourceBranchName)
 
 stages:
+- stage: Pretest
+  jobs:
+  - job: static_analysis
+    displayName: "Static Analysis"
+    timeoutInMinutes: 10
+    continueOnError: true
+    pool: ubuntu-20.04
+    steps:
+    - template: .azure-pipelines/pre-commit-check.yml
+
 - stage: Build
 
   jobs: