Update to go1.18

Mostly for github actions updating, as the code currently has no external deps.

Add dependabot config

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 2 to 3.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@v2...v3)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

…setup-go-3

Bump actions/setup-go from 2 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.1.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3.1.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

…checkout-3.1.0

Bump actions/checkout from 2 to 3.1.0

Bumps [golangci/golangci-lint-action](https://github.com/golangci/golangci-lint-action) from 2 to 3.
- [Release notes](https://github.com/golangci/golangci-lint-action/releases)
- [Commits](golangci/golangci-lint-action@v2...v3)

---
updated-dependencies:
- dependency-name: golangci/golangci-lint-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

…/golangci-lint-action-3

Bump golangci/golangci-lint-action from 2 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.1.0 to 3.3.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3.1.0...v3.3.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

…checkout-3.3.0

Bump actions/checkout from 3.1.0 to 3.3.0

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 3 to 4.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@v3...v4)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.3.0 to 3.5.3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3.3.0...v3.5.3)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

…setup-go-4

Bump actions/setup-go from 3 to 4

…checkout-3.5.3

Bump actions/checkout from 3.3.0 to 3.5.3