Automation of Branch Names for a Simple Standard Build Workflow

It should be possible to create and use a standard workflow that automatically takes into account the branch name and our convention about the output brand a prototype is here: https://github.com/apache/petri/blob/dfoulks/pelican-gha/.github/workflows/build-pelican.yml

Note that the following part covers the automation of changes on branches:

```
on:
push:
branches:
- 'preview/**'
pull_request:
branches:
- 'preview/**'
workflow_dispatch:
```

We might need an excludes.

The other part computes the branch names and should become part of our standard action:

```
jobs:
build-pelican:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
with:
ref: ${{ github.event.inputs.branch || github.head_ref || github.ref }}
- name: Determine branch name
id: get_branch
run: |
# Get the current branch name
echo "BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD)" >> $GITHUB_ENV
- name: Branch
run: |
echo "Branch: ${{ env.BRANCH_NAME }}"
if [ "${{ env.BRANCH_NAME }}" == "${{ github.event.repository.default_branch }}" ]; then
echo "OUTPUT_BRANCH=asf-site" >> $GITHUB_ENV
else
echo "OUTPUT_BRANCH=${{ env.BRANCH_NAME }}-staging" >> $GITHUB_ENV
fi
- name: Pelican Build
uses: apache/infrastructure-actions/pelican@main
with:
destination: ${{ env.OUTPUT_BRANCH }}
```

Making the destination part of the automation means that the pelican action should babe able to need no inputs.