Update goreleaser.yml (#726)

Use 	ubuntu-20.04 image to solve libc error.

<!-- < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < ☺
v           ✰  Thanks for creating a PR! You're awesome! ✰
v Please note that maintainers will only review those PRs with a
completed PR template.
☺ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >  -->

## Purpose of Changes and their Description

## Link(s) to Ticket(s) or Issue(s) resolved by this PR

## Are these changes tested and documented?

- [ ] If tested, please describe how. If not, why tests are not needed.
- [ ] If documented, please describe where. If not, describe why docs
are not needed.
- [ ] Added to `Unreleased` section of `CHANGELOG.md`?

## Still Left Todo

*Fill this out if this is a Draft PR so others can help.*

.github/workflows/goreleaser.yml

@@ -10,7 +10,7 @@ permissions:
 
 jobs:
   goreleaser:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       -
         name: Checkout