Add goimports to make fmt (#2456)

## Description

Missed adding it to `make fmt` earlier

## Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No 

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [x] 🧹 Tech Debt/Cleanup

src/Makefile

@@ -17,6 +17,7 @@ lint: check-lint-version
 
 fmt:
 	gofumpt -w .
+	goimports -w .
 	gci write --skip-generated -s 'standard,default,prefix(github.com/alcionai/corso)' .
 
 check-lint-version: check-lint