STRIPES-934 migrate from upload-artifact@v2 to v4 (#70)

* STRIPES-934 migrate from upload-artifact@v2 to v4

Migrate to shared workflows (the REAL STRIPES-934) under a separate PR;
this work just updates the upload-artifact version, a change which
doesn't require any special GitHub privileges and will immediately
unblock us.

Refs STRIPES-934 (not)

* whoops; missed one

.github/workflows/build-npm-release.yml

@@ -152,7 +152,7 @@ jobs:
  comment_title: Jest Unit Test Statistics
 
  - name: Publish Jest coverage report
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: always()
  with:
  name: jest-coverage-report
@@ -170,15 +170,15 @@ jobs:
  comment_title: BigTest Unit Test Statistics
 
  - name: Publish BigTest coverage report
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: always()
  with:
  name: bigtest-coverage-report
  path: ${{ env.BIGTEST_COVERAGE_REPORT_DIR }}
  retention-days: 30
 
  - name: Publish yarn.lock
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: failure()
  with:
  name: yarn.lock

.github/workflows/build-npm.yml

@@ -95,7 +95,7 @@ jobs:
  comment_title: Jest Unit Test Statistics
 
  - name: Publish Jest coverage report
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: always()
  with:
  name: jest-coverage-report
@@ -113,15 +113,15 @@ jobs:
  comment_title: BigTest Unit Test Statistics
 
  - name: Publish BigTest coverage report
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: always()
  with:
  name: bigtest-coverage-report
  path: ${{ env.BIGTEST_COVERAGE_REPORT_DIR }}
  retention-days: 30
 
  - name: Publish yarn.lock
- uses: actions/upload-artifact@v2
+ uses: actions/upload-artifact@v4
  if: failure()
  with:
  name: yarn.lock