ci: use go tool (#25)

## Description

Tool versions were not pinned to the repository: this caused issues with upgrades.

## Changes

- Use `go tool` for `checkmake`, `gremlins`, `golangci-lint`, `godoc` and `govulncheck`.

### Design Decisions

## Checklist

- [x] Tests pass
- [x] Docs updated

Reviewed-on: #25
Co-authored-by: M.V. Hutz <git@maximhutz.me>
Co-committed-by: M.V. Hutz <git@maximhutz.me>

.gitea/workflows/ci.yml

@@ -32,9 +32,8 @@ jobs:
       - name: Check go mod tidy
         run: go mod tidy && git diff --exit-code go.mod go.sum
 
-      - uses: golangci/golangci-lint-action@v7
-        with:
-          version: latest
+      - name: Run linter
+        run: make lint-go
 
   lint-makefile:
     name: Makefile Lint
@@ -46,9 +45,6 @@ jobs:
         with:
           go-version-file: go.mod
 
-      - name: Install gremlins
-        run: go install github.com/checkmake/checkmake/cmd/checkmake@latest
-
       - name: Run mutation tests
         run: make lint-makefile
 
@@ -96,8 +92,5 @@ jobs:
         with:
           go-version-file: go.mod
 
-      - name: Install gremlins
-        run: go install github.com/go-gremlins/gremlins/cmd/gremlins@latest
-
       - name: Run mutation tests
         run: make test-mutation