feat: Add support for checking all changes of PR

[stokkie90]

This Adds support for checking entire PR context instead of only the last commit.
Also fixes a bunch of errors making sure it uses the correct Repo when looping over the list. When setting RepoConfig it Assigned the object to the last one in the loop of Repositories. Resulting in wrong comparison.

Log of the RepoConfig error:

DEBUG (event): Processing repo {"visibility":"internal","name":"sdlc-test-changelog","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Process normally... Not a SubOrg config change or SubOrg config was changed and this repo is part of it. {"owner":"Org-123","repo":"sdlc-test-changelog"} suborg config undefined
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Processing Merged repoConfig {"visibility":"internal","name":"sdlc-test-changelog","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): sdlc-poc not in restricted repos admin,.github,safe-settings
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Processing repo {"visibility":"internal","name":"sdlc-poc","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Process normally... Not a SubOrg config change or SubOrg config was changed and this repo is part of it. {"owner":"Org-123","repo":"sdlc-poc"} suborg config undefined
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Processing Merged repoConfig {"visibility":"internal","name":"sdlc-poc","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): data-analysis-eda not in restricted repos admin,.github,safe-settings
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Processing repo {"visibility":"internal","name":"data-analysis-eda","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Process normally... Not a SubOrg config change or SubOrg config was changed and this repo is part of it. {"owner":"Org-123","repo":"data-analysis-eda"} suborg config undefined
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Processing Merged repoConfig {"visibility":"internal","name":"data-analysis-eda","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
    
 #### FROM HERE IT ONLY USED `test-repo-1`   
DEBUG (octokit): GitHub request: GET https://api.github.com/repos/Org-123/spec-api-Org-123-deep-integration - 200
DEBUG (event): Repo Org-123/spec-api-Org-123-deep-integration is not archived, proceed as usual.
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): found a matching repoconfig for this repo {"visibility":"internal","name":"data-analysis-eda","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): suborg config for spec-api-Org-123-deep-integration  is undefined
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): consolidated config is {"restrictedRepos":["admin",".github","safe-settings"],"repository":{"visibility":"internal","name":"data-analysis-eda","org":"Org-123"}}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): Syncing Repo data-analysis-eda
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (octokit): GitHub request: GET https://api.github.com/repos/Org-123/api-store - 200
DEBUG (event): Repo Org-123/api-store is not archived, proceed as usual.
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): found a matching repoconfig for this repo {"visibility":"internal","name":"data-analysis-eda","org":"Org-123"}
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
DEBUG (event): suborg config for api-store  is undefined
    id: "1e8b1e00-f5c9-11ef-8072-0096effcb449"
    
    
# Found matching config will result always in `data-analysis-eda` being used
    ```

PR Overview

This PR adds support for checking an entire pull request’s changes rather than only the last commit and fixes a bug with repo configuration assignment. Key changes include:

• Introducing a new environment flag (PR_USE_BASE_SHA) to control base SHA selection in check runs.
• Fixing the assignment of RepoConfig to avoid unintended mutation by using a new object copy.
• Updating debug logging in rulesets and settings to improve clarity during processing.

Reviewed Changes

File	Description
index.js	Adjusts SHA selection logic based on the new PR_USE_BASE_SHA flag for check runs.
lib/env.js	Introduces the new environment variable PR_USE_BASE_SHA with a default value of 'false'.
lib/plugins/rulesets.js	Updates logging to use the repository owner for clarity when fetching rulesets.
lib/settings.js	Adds debug logs at the start of sync routines, fixes the RepoConfig assignment to avoid mutation, and refines the filtering of results in nop mode.

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (3)

lib/settings.js:306

• Creating a new object for repoConfig prevents mutating the original configuration, which avoids side effects in later processing. Please verify that all downstream consumers correctly handle the new object reference.

repoConfig = Object.assign({}, repoConfig, { name: repo.repo, org: repo.owner })

lib/settings.js:867

• [nitpick] Defaulting to an empty array when res is not an array might discard valid result data; confirm that res is always expected to be an array in nop mode.

const results = Array.isArray(res) ? res.flat(3).filter(r => r) : [];

lib/plugins/rulesets.js:31

• [nitpick] Using 'this.repo.owner' for logging improves clarity regarding the organization context; ensure that this change is consistent with how the organization is referenced throughout the code.

this.log.debug(`Getting all rulesets for the org ${this.repo.owner}`)