ci(i): Add action to ensure tidyness (#2697)

## Relevant issue(s)
Resolves ##2695

## Description

### Backstory
- A commit (c42e7ee) broke mod tidy command recently
- Which was fixed in the next commit in this PR:
#2548
- Some head scratching was done to find out that mod tidy needed a
minimum version, hence the current pinned mod tidy

There are 2 things being checked within the new added action:
1) That the backstory doesn't happen again (`make tidy` isn't broken).
2) `make tidy` is ran and up to date.

NOTE: `(2)` above I am not sure if we want to keep, or not I would be
okay with just `(1)`. However here are some reasons why you would want
`(2)`:
- always be in `tidy state`
- one less command to do at release stage.

## How has this been tested?
- Action that failed when `make tidy` was broken:
https://github.com/sourcenetwork/defradb/actions/runs/9422665720/job/25959440810?pr=2697

- Action that failed when `make tidy` was not up to date (i.e. not
tidy):

https://github.com/sourcenetwork/defradb/actions/runs/9422726089/job/25959622978?pr=2697


Specify the platform(s) on which this was tested:
- WSL2

.github/workflows/check-tidy.yml

@@ -0,0 +1,59 @@
+# Copyright 2024 Democratized Data Foundation
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+# This workflow checks that go mod tidy command we have set for the specific
+# go version is not broken, for example `go mod tidy -go=1.21.3`. This
+# can cause some head scratching at times, so better catch this in the PR.
+#
+# Inaddition to that also checks that we are currently in a `tidy` state.
+name: Check Tidy Workflow
+
+on:
+  pull_request:
+    branches:
+      - master
+      - develop
+
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+    branches:
+      - master
+      - develop
+
+jobs:
+  check-tidy:
+    name: Check mod tidy job
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - name: Checkout code into the directory
+        uses: actions/checkout@v3
+
+      - name: Setup Go environment explicitly
+        uses: actions/setup-go@v3
+        with:
+          go-version: "1.21"
+          check-latest: true
+
+      # This checks mod tidy is not broken.
+      - name: Check mod tidy
+        run: make tidy
+
+      # This checks mod tidy is up to date.
+      - name: Check no new changes exist
+        uses: tj-actions/verify-changed-files@v20
+        with:
+          fail-if-changed: true
+          files: |
+             go.mod
+             go.sum