chore: display test summary on GH actions

[mdelapenya]

What does this PR do?

It adds the test-summary/action GH action (https://github.com/test-summary/action) to both GH actions, which produces an easy-to-read summary of project's test data as part of the GitHub Actions CI/CD workflow.

Why is it important?

This will help us understand at-a-glance the impact to the changes in our pull requests.

Screenshots

• Docker pipeline: https://github.com/testcontainers/testcontainers-go/actions/runs/2570193811
• Podman pipeline: https://github.com/testcontainers/testcontainers-go/actions/runs/2570193809

[codecov]

Codecov Report

Merging #473 (9d04b74) into main (b5ff9a2) will decrease coverage by 0.15%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #473      +/-   ##
==========================================
- Coverage   69.79%   69.64%   -0.16%     
==========================================
  Files          21       21              
  Lines        1947     1947              
==========================================
- Hits         1359     1356       -3     
- Misses        472      474       +2     
- Partials      116      117       +1     

Impacted Files	Coverage Δ
docker.go	70.20% <0.00%> (-0.35%)	⬇️

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[gianarb]

Nice!