Bump golang from 1.20 to 1.21 in /internal/test/e2e/databasesql (#314)

Bumps golang from 1.20 to 1.21.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

internal/test/e2e/databasesql/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.20
+FROM golang:1.21
 WORKDIR /sample-app
 COPY . .
 RUN go build -o main