Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/builder_factory.yml

@@ -31,7 +31,7 @@ jobs:
 #          - esp32S3_16M_debug
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: PIP Cache
         id: cache-pip
         uses: actions/cache@v4

.github/workflows/mk_release_assets.yml

@@ -21,7 +21,7 @@ jobs:
     if: github.repository == 'vortigont/FireLamp_JeeUI'
     continue-on-error: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ inputs.refToBuild }}
       - name: PIP Cache

.github/workflows/pio_build.yml

@@ -51,7 +51,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: PIP Cache
         id: cache-pip