fix: Update mdbook-mermaid installation to use dynamic version

The workflow was failing because it was trying to download v0.16.0
but the latest release is v0.15.0. Changed to dynamically fetch the
latest version from GitHub API to make it future-proof.

Author: ammario

.github/workflows/docs.yml

@@ -30,7 +30,8 @@ jobs:
 
       - name: Install mdbook-mermaid
         run: |
-          curl -sSL https://github.com/badboy/mdbook-mermaid/releases/latest/download/mdbook-mermaid-v0.16.0-x86_64-unknown-linux-gnu.tar.gz | tar -xz
+          VERSION=$(curl -s https://api.github.com/repos/badboy/mdbook-mermaid/releases/latest | grep tag_name | cut -d '"' -f 4)
+          curl -sSL "https://github.com/badboy/mdbook-mermaid/releases/download/${VERSION}/mdbook-mermaid-${VERSION}-x86_64-unknown-linux-gnu.tar.gz" | tar -xz
           sudo mv mdbook-mermaid /usr/local/bin/
           mdbook-mermaid install .