feat: publish rpc-proxy Dockerfile on tag

[freemanzMrojo]

Description

As part of the release, when creating a tag we will publish in Docker Hub the rpc-proxy image named vechain/sdk-rpc-proxy.

This is one of the steps needed to complete #1319 .

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

By running the pipeline for the PR. It is possible though that the pipeline could break the first time when creating the tag.

Test Configuration:

• Node.js Version: 20.17.0
• Yarn Version: 1.22.19

Checklist:

• My code follows the coding standards of this project
• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• New and existing integration tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have not added any vulnerable dependencies to my code

[github-actions]

Test Coverage

Summary

Lines	Statements	Branches	Functions
	99.06% (4352/4393)	97.71% (1413/1446)	99.11% (896/904)

Title	Tests	Skipped	Failures	Errors	Time
core	808	0 💤	0 ❌	0 🔥	2m 21s ⏱️
network	734	0 💤	0 ❌	0 🔥	5m 14s ⏱️
errors	42	0 💤	0 ❌	0 🔥	16.696s ⏱️
logging	3	0 💤	0 ❌	0 🔥	17.211s ⏱️
hardhat-plugin	19	0 💤	0 ❌	0 🔥	59.412s ⏱️
aws-kms-adapter	23	0 💤	0 ❌	0 🔥	1m 16s ⏱️
ethers-adapter	5	0 💤	0 ❌	0 🔥	1m 11s ⏱️
rpc-proxy	37	0 💤	0 ❌	0 🔥	1m 6s ⏱️