False positive for the rule `actions/pr-on-self-hosted-runner`

**Description of the false positive**

False positive for the rule `actions/pr-on-self-hosted-runner` when `runs-on` is an expression.

We have an expression for whether the job runs on `windows-latest` or `ubuntu-latest`. Neither are self hosted.
```
runs-on: ${{ ((matrix.language == 'c-cpp' || matrix.language == 'csharp') && 'windows-latest') || 'ubuntu-latest' }}
```

**Code samples or links to source code**

```
name: "CodeQL Advanced"

on:
push:
branches: [ "master" ]
pull_request:
branches: [ "master" ]
schedule:
- cron: '42 8 * * 4'
workflow_dispatch:

jobs:
analyze:
name: Analyze (${{ matrix.language }})
# Runner size impacts CodeQL analysis time. To learn more, please see:
# - https://gh.io/recommended-hardware-resources-for-running-codeql
# - https://gh.io/supported-runners-and-hardware-resources
# - https://gh.io/using-larger-runners (GitHub.com only)
# Consider using larger runners or machines with greater resources for possible analysis time improvements.
runs-on: ${{ ((matrix.language == 'c-cpp' || matrix.language == 'csharp') && 'windows-latest') || 'ubuntu-latest' }}
env:
CONAN_PASSWORD: ${{ secrets.RHAPSODY_ARTIFACTORY_KEY }}
CONAN_LOGIN_USERNAME: ${{ vars.RHAPSODY_ARTIFACTORY_USER }}

permissions:
# required for all workflows
security-events: write

# required to fetch internal or private CodeQL packs
packages: read

# only required for workflows in private repositories
actions: read
contents: read

strategy:
fail-fast: false
matrix:
include:
- language: actions
build-mode: none
queries: actions-all
- language: c-cpp
build-mode: manual
- language: csharp
build-mode: manual
- language: java-kotlin
build-mode: none # This mode only analyzes Java. Set this to 'autobuild' or 'manual' to analyze Kotlin too.
- language: javascript-typescript
build-mode: none
- language: python
build-mode: none
# CodeQL supports the following values keywords for 'language': 'actions', 'c-cpp', 'csharp', 'go', 'java-kotlin', 'javascript-typescript', 'python', 'ruby', 'swift'
# Use `c-cpp` to analyze code written in C, C++ or both
# Use 'java-kotlin' to analyze code written in Java, Kotlin or both
# Use 'javascript-typescript' to analyze code written in JavaScript, TypeScript or both
# To learn more about changing the languages that are analyzed or customizing the build mode for your analysis,
# see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning.
# If you are analyzing a compiled language, you can modify the 'build-mode' for that language to customize how
# your codebase is analyzed, see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages
steps:
- name: Checkout repository
uses: actions/checkout@v4

# Add any setup steps before running the `github/codeql-action/init` action.
# This includes steps like installing compilers or runtimes (`actions/setup-node`
# or others). This is typically only required for manual builds.
# - name: Setup runtime (example)
# uses: actions/setup-example@v1

# Initializes the CodeQL tools for scanning.
- name: Initialize CodeQL
uses: github/codeql-action/init@v3
with:
languages: ${{ matrix.language }}
build-mode: ${{ matrix.build-mode }}
queries: ${{ matrix.queries }}
# If you wish to specify custom queries, you can do so here or in a config file.
# By default, queries listed here will override any specified in a config file.
# Prefix the list here with "+" to use these queries and those in the config file.

# For more details on CodeQL's query packs, refer to: https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
# queries: security-extended,security-and-quality

- name: Perform CodeQL Analysis
uses: github/codeql-action/analyze@v3
with:
category: "/language:${{matrix.language}}"
```

**URL to the alert on GitHub code scanning (optional)**

Start by reproducing the `actions/pr-on-self-hosted-runner` alert with the expression-based `runs-on` workflow shown in the issue. Locate the rule implementation and its tests, then update the behavior so this expression selecting `windows-latest` or `ubuntu-latest` is not reported as self-hosted; add or adjust a regression test and verify the alert is gone.

Rédigé par le modèle d'indexation à partir du texte de l'issue.