Fix and re-instate automatic releases

[nokome]

I've tried several things to solve an error when semantic-release attempts to release the @stencila/encoda package e.g.

https://github.com/stencila/encoda/actions/runs/10443621470/job/28917233208#step:6:179

Note also this message:

https://github.com/stencila/encoda/actions/runs/10443621470/job/28917233208#step:6:123

I am able to publish the package with the token manually, so I do not think that the token is, in fact, invalid. Rather it seems to be a problem with semantic-release and how it authenticates with NPM.

The things I have tried to fix this include:

• updating semantic-release and @semantic-release/git
• renaming the env var for the token
• adding a .npmrc file

Until this is resolved I have disabled the release step in CI so automatic releases are not done there and will need to be done manually.