[StepSecurity] Apply security best practices (#155)

## Summary

This pull request is created by
[StepSecurity](https://app.stepsecurity.io/securerepo) at the request of
@rsned. Please merge the Pull Request to incorporate the requested
changes. Please tag @rsned on your message if you have any questions
related to the PR.
## Security Fixes

### Least Privileged GitHub Actions Token Permissions

The GITHUB_TOKEN is an automatically generated secret to make
authenticated calls to the GitHub API. GitHub recommends setting minimum
token permissions for the GITHUB_TOKEN.

- [GitHub Security
Guide](https://docs.github.com/en/actions/security-guides/automatic-token-authentication#using-the-github_token-in-a-workflow)
- [The Open Source Security Foundation (OpenSSF) Security
Guide](https://github.com/ossf/scorecard/blob/main/docs/checks.md#token-permissions)
### Pinned Dependencies

GitHub Action tags and Docker tags are mutable. This poses a security
risk. GitHub's Security Hardening guide recommends pinning actions to
full length commit.

- [GitHub Security
Guide](https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-third-party-actions)
- [The Open Source Security Foundation (OpenSSF) Security
Guide](https://github.com/ossf/scorecard/blob/main/docs/checks.md#pinned-dependencies)
### Keeping your actions up to date with Dependabot

With Dependabot version updates, when Dependabot identifies an outdated
dependency, it raises a pull request to update the manifest to the
latest version of the dependency. This is recommended by GitHub as well
as The Open Source Security Foundation (OpenSSF).

- [GitHub Security
Guide](https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot)
- [The Open Source Security Foundation (OpenSSF) Security
Guide](https://github.com/ossf/scorecard/blob/main/docs/checks.md#dependency-update-tool)


## Feedback
For bug reports, feature requests, and general feedback; please email
[email protected]. To create such PRs, please visit
https://app.stepsecurity.io/securerepo.


Signed-off-by: StepSecurity Bot <[email protected]>

Signed-off-by: StepSecurity Bot <[email protected]>

Author: step-security-bot

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: daily
+
+  - package-ecosystem: gomod
+    directory: /
+    schedule:
+      interval: daily

.github/workflows/go.yml

@@ -9,15 +9,18 @@ on:
   pull_request:
     branches: [ "master" ]
 
+permissions:
+  contents: read
+
 jobs:
 
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
     - name: Set up Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@0aaccfd150d50ccaeb58ebd88d36e91967a5f35b # v5.4.0
       with:
         go-version-file: 'go.mod'