Add GH Action to push to Docker Registry

[niccoloraspa]

Description

This PR adds a GitHub Action to automatically build and push a new osmosis docker image on every new tag release.

When a new tag v7.0.5 is released:

• osmolabs/osmosis:7.0.5 is pushed
• osmolabs/osmosis:latest is updated
• osmolabs/osmosis:7.0 is created/updated
• osmolabs/osmosis:7 is created/updated

I have dropped the v from the docker tag, which is the recommend approach. So:

🚫 docker pull osmolabs/osmosis:v7.0.5
✅ docker pull osmolabs/osmosis:7.0.5

I will keep both in the registry for now so people can still pull previous images without disruption.
Moving forward only tags without the v will be pushed.

---

For contributor use:

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

[codecov-commenter]

Codecov Report

Merging #1105 (f02c282) into main (72dee1f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1105   +/-   ##
=======================================
  Coverage   20.94%   20.94%           
=======================================
  Files         199      199           
  Lines       25429    25429           
=======================================
  Hits         5326     5326           
  Misses      19140    19140           
  Partials      963      963           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 72dee1f...f02c282. Read the comment docs.

[ValarDragon]

Awesome!! This is really exciting, thanks for automating this step!

[daniel-farina]

amazing!!