ci: cache eslint and tsc results between ci runs (#33304)

## **Description**

`yarn lint` and `yarn lint:tsc` both run cold on every CI invocation:
`.eslintcache` and `tsconfig.tsbuildinfo` are gitignored, and the
`scripts` job in `ci.yml` does a fresh `actions/checkout` with no step
restoring them, so ESLint's `--cache` flag and TypeScript's
`incremental: true` option never actually get to skip anything in CI —
every run re-lints and re-type-checks the entire repo from scratch.

This adds two rolling caches to the `scripts` job, scoped to their
respective matrix entries:

- `lint` → restores/saves `.eslintcache`
- `lint:tsc` → restores/saves `tsconfig.tsbuildinfo`

Both use a `key` that includes `github.run_id` (always a miss) with a
`restore-keys` prefix fallback — this is the pattern documented in
[`actions/cache`'s own "Update a cache"
guidance](https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache),
needed because cache entries are immutable and can't be overwritten in
place. The net effect: each run restores the most recent eligible cache
(same branch, base branch, or `main`, per GitHub's cache access rules),
lets the tool re-validate file hashes itself, and saves a fresh cache at
the end — so most runs only need to re-lint/re-check files that actually
changed instead of the whole repo.

## **Changelog**

CHANGELOG entry: null

## **Related issues**

Fixes:

## **Manual testing steps**

N/A — CI-only configuration change with no in-app behavior to verify.
Validated by observing the `Restore ESLint cache` / `Restore TypeScript
incremental build cache` steps and the resulting `lint` / `lint:tsc` job
durations across consecutive CI runs on this PR and after merging to
`main`.

## **Screenshots/Recordings**

### **Before**

N/A

### **After**

N/A

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

#### Performance checks (if applicable)

- [x] I've tested on Android
- [x] I've tested with a power user scenario
- [x] I've instrumented key operations with Sentry traces for production
performance metrics

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

Made with [Cursor](https://cursor.com)

Author: tommasini

.github/workflows/ci.yml

@@ -307,6 +307,22 @@ jobs:
           command: yarn install --immutable
       - name: Clean state and following up dependencies installation
         run: yarn setup:github-ci --node
+      - name: Restore ESLint cache
+        if: ${{ matrix.scripts == 'lint' }}
+        uses: actions/cache@v4
+        with:
+          path: .eslintcache
+          key: eslintcache-${{ runner.os }}-${{ github.run_id }}
+          restore-keys: |
+            eslintcache-${{ runner.os }}-
+      - name: Restore TypeScript incremental build cache
+        if: ${{ matrix.scripts == 'lint:tsc' }}
+        uses: actions/cache@v4
+        with:
+          path: tsconfig.tsbuildinfo
+          key: tsbuildinfo-${{ runner.os }}-${{ github.run_id }}
+          restore-keys: |
+            tsbuildinfo-${{ runner.os }}-
       - run: yarn ${{ matrix['scripts'] }}
       - name: Require clean working directory
         shell: bash
@@ -1338,7 +1354,13 @@ jobs:
     permissions:
       contents: read
       id-token: write
-    needs: [get_requirements, build-android-apks, smart-e2e-selection, prepare-e2e-timings]
+    needs:
+      [
+        get_requirements,
+        build-android-apks,
+        smart-e2e-selection,
+        prepare-e2e-timings,
+      ]
     uses: ./.github/workflows/run-e2e-smoke-tests-android.yml
     with:
       changed_files: ${{ needs.get_requirements.outputs.changed_files }}
@@ -1392,7 +1414,13 @@ jobs:
     permissions:
       contents: read
       id-token: write
-    needs: [get_requirements, ios-tests-ready, smart-e2e-selection, prepare-e2e-timings]
+    needs:
+      [
+        get_requirements,
+        ios-tests-ready,
+        smart-e2e-selection,
+        prepare-e2e-timings,
+      ]
     uses: ./.github/workflows/run-e2e-smoke-tests-ios.yml
     with:
       changed_files: ${{ needs.get_requirements.outputs.changed_files }}