improve codecov GHA config with metadata

[reactive-firewall]

          Should update the config to use the new values better.

        token: ${{ secrets.CODECOV_TOKEN }}
        job_code: ${{ join( [github.run_id, github.run_number], '-' ) }}
        os: ${{ matrix.os }}

Originally posted by @reactive-firewall in #194 (comment)

[reactive-firewall]

ℹ️ informative ref: https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/evaluate-expressions-in-workflows-and-actions

[reactive-firewall]

Consider

name: CI-TESTS
# Continuous Integration workflow for post-MATs additional testing, and validating of the project.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true

[reactive-firewall]

Also consider the following improvements:

Security-focused action versioning

Excellent security practice using specific commit hashes instead of version tags. This prevents potential supply chain attacks by ensuring the exact version of actions being used.

Consider defining the action versions as environment variables to maintain DRY principle:

env:
  YAMLLINT_ACTION_VERSION: 2576378a8e339169678f9939646ee3ee325e845c # v3.1.1
  CHECKOUT_ACTION_VERSION: 11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

Then use them like:

uses: actions/checkout@${{ env.CHECKOUT_ACTION_VERSION }}
uses: ibiqlik/action-yamllint@${{ env.YAMLLINT_ACTION_VERSION }}

---

Also consider refactoring PIP installs:

-          pip install --upgrade "pip>=24.3.1" "setuptools>=75.0" "wheel>=0.44" "build>=1.2.1";
-          pip install -r ./requirements.txt ;
-          pip install -r ./tests/requirements.txt || true ;
-          pip install --upgrade -r ./docs/requirements.txt || true ;
+          # Update core build tools
+          pip install --upgrade \
+            "pip>=24.3.1" \
+            "setuptools>=75.0" \
+            "wheel>=0.44" \
+            "build>=1.2.1"
+
+          # Install project dependencies
+          pip install -r ./requirements.txt
+
+          # Install optional dependencies
+          for req in ./tests/requirements.txt ./docs/requirements.txt; do
+            if [ -f "$req" ]; then
+              pip install -r "$req" || echo "Warning: Failed to install $req"
+            fi
+          done