ci: use actions/checkout@v4

now that the rss-to-issues action uses node 20, it's time to update the
actions we use for our CI jobs, to also use node 20.
actions/checkout@v2 in verify-dist.yml was so old that GitHub was forcing
it to run under node 16 insted of node 12 which it was designed to run
under.

actions/github-script does not support node 20 yet, though. [1]

[1] actions/github-script#421

Signed-off-by: Matthias Aßhauer <mha1993@live.de>

Author: rimrul

.github/workflows/release-tag.yml

@@ -13,7 +13,7 @@ jobs:
     name: Publish GitHub Release from tag
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           token: ${{ secrets.PUSH_RELEASE_TRAINS_PAT }}
           fetch-depth: 0

.github/workflows/verify-dist.yml

@@ -11,7 +11,7 @@ jobs:
     name: Build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - run: npm ci
       - run: npm run lint
       - run: npm run test