Lack of both steps and uses isn't flagged as an error

**Describe the bug**
A clear and concise description of what the bug is.

**To Reproduce**
Steps to reproduce the behavior:
1. With this workflow `csharp-qltest.yml`:
```yml
name: "C#: Run QL Tests"

on:
push:
paths:
- "csharp/**"
- "shared/**"
- .github/actions/fetch-codeql/action.yml
- codeql-workspace.yml
branches:
- main
- "rc/*"
pull_request:
paths:
- "csharp/**"
- "shared/**"
- .github/workflows/csharp-qltest.yml
- .github/actions/fetch-codeql/action.yml
- codeql-workspace.yml
branches:
- main
- "rc/*"

defaults:
run:
working-directory: csharp

jobs:
qlupgrade:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: ./.github/actions/fetch-codeql
- name: Check DB upgrade scripts
run: |
echo >empty.trap
codeql dataset import -S ql/lib/upgrades/initial/semmlecode.csharp.dbscheme testdb empty.trap
codeql dataset upgrade testdb --additional-packs ql/lib
diff -q testdb/semmlecode.csharp.dbscheme ql/lib/semmlecode.csharp.dbscheme
- name: Check DB downgrade scripts
run: |
echo >empty.trap
rm -rf testdb; codeql dataset import -S ql/lib/semmlecode.csharp.dbscheme testdb empty.trap
codeql resolve upgrades --format=lines --allow-downgrades --additional-packs downgrades \
--dbscheme=ql/lib/semmlecode.csharp.dbscheme --target-dbscheme=downgrades/initial/semmlecode.csharp.dbscheme |
xargs codeql execute upgrades testdb
diff -q testdb/semmlecode.csharp.dbscheme downgrades/initial/semmlecode.csharp.dbscheme

choose-runner:
runs-on: ubuntu-latest
outputs:
mac-12: ${{ vars.use-large-mac-runners-for-speed && 'mac-12-xl' || 'mac-12' }}
ubuntu-latest: ${{ vars.use-large-linux-runners-for-speed && 'ubuntu-latest-xl' || 'ubuntu-latest' }}
windows-latest: ${{ vars.use-large-win-runners-for-speed && 'windows-latest-xl' || 'windows-latest' }}

qltest:
needs: choose-runner
runs-on: ${{ needs.choose-runner.outputs.ubuntu-latest }}
strategy:
fail-fast: false
matrix:
slice: ["1/2", "2/2"]
steps:
- uses: actions/checkout@v4
- uses: ./csharp/actions/create-extractor-pack
- name: Cache compilation cache
id: query-cache
uses: ./.github/actions/cache-query-compilation
with:
key: csharp-qltest-${{ matrix.slice }}
- name: Run QL tests
run: |
codeql test run --threads=0 --ram 50000 --slice ${{ matrix.slice }} --search-path extractor-pack --check-databases --check-undefined-labels --check-repeated-labels --check-redefined-labels --consistency-queries ql/consistency-queries ql/test --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
env:
GITHUB_TOKEN: ${{ github.token }}
unit-tests:
strategy:
matrix:
os: [ubuntu-latest, windows-2019]
runs-on: ${{ matrix.os }}
steps:
- uses: actions/checkout@v4
- name: Setup dotnet
uses: actions/setup-dotnet@v4
with:
dotnet-version: 8.0.100
- name: Extractor unit tests
run: |
dotnet test -p:RuntimeFrameworkVersion=8.0.0 extractor/Semmle.Util.Tests
dotnet test -p:RuntimeFrameworkVersion=8.0.0 extractor/Semmle.Extraction.Tests
dotnet test -p:RuntimeFrameworkVersion=8.0.0 autobuilder/Semmle.Autobuild.CSharp.Tests
dotnet test -p:RuntimeFrameworkVersion=8.0.0 "${{ github.workspace }}/cpp/autobuilder/Semmle.Autobuild.Cpp.Tests"
shell: bash
stubgentest:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: ./csharp/actions/create-extractor-pack
- name: Run stub generator tests
run: |
# Generate (Asp)NetCore stubs
STUBS_PATH=stubs_output
python3 scripts/stubs/make_stubs_nuget.py webapp Swashbuckle.AspNetCore.Swagger 6.5.0 "$STUBS_PATH"
rm -rf ql/test/resources/stubs/_frameworks
# Update existing stubs in the repo with the freshly generated ones
mv "$STUBS_PATH/output/stubs/_frameworks" ql/test/resources/stubs/
git status
codeql test run --threads=0 --search-path extractor-pack --check-databases --check-undefined-labels --check-repeated-labels --check-redefined-labels --consistency-queries ql/consistency-queries -- ql/test/library-tests/dataflow/flowsources/aspremote
env:
GITHUB_TOKEN: ${{ github.token }}
```

2. Look at the choose-runner job

**Expected behavior**

According to GitHub, this job isn't valid:
https://github.com/jsoref/codeql/actions/runs/7712430252
> [Invalid workflow file: .github/workflows/csharp-qltest.yml#L1](https://github.com/jsoref/codeql/actions/runs/7712430252/workflow)
No steps defined in `steps` and no workflow called in `uses` for the following jobs: choose-runner

Generally if a workflow isn't valid, this extension will complain, e.g. if I add just `steps:`:

**Screenshots**
[Invalid workflow file: .github/workflows/csharp-qltest.yml#L1](https://github.com/jsoref/codeql/actions/runs/7712430252/workflow)
No steps defined in `steps` and no workflow called in `uses` for the following jobs: choose-runner

**Extension Version**
`v0.26.2`

**Additional context**