`Unexpected token : in JSON at position 3` for rc builds

As part of https://github.com/nodejs/build/issues/3524 I've manually run the promotion script on the non-release builds, and I've noticed lots of errors like the following for the rc builds:

SyntaxError: Unexpected token : in JSON at position 3
    at JSON.parse (<anonymous>)
    at /usr/lib/node_modules/nodejs-dist-indexer/dist-indexer.js:119:19
    at BufferListStream._callback (/usr/lib/node_modules/nodejs-dist-indexer/dist-indexer.js:101:5)
    at BufferListStream.end (/usr/lib/node_modules/nodejs-dist-indexer/node_modules/bl/bl.js:65:10)
    at DestroyableTransform.onend (/usr/lib/node_modules/nodejs-dist-indexer/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:523:10)
    at Object.onceWrapper (node:events:627:28)
    at DestroyableTransform.emit (node:events:525:35)
    at /usr/lib/node_modules/nodejs-dist-indexer/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:965:16
    at processTicksAndRejections (node:internal/process/task_queues:78:11)
(ignoring error fetching npm version for node/v0.10.44-rc.1)

My guess would be that e.g. v0.10.44-rc.1 isn't mapping to a valid git reference when the substitution is done for https://github.com/nodejs/nodejs-dist-indexer/blob/860a8b4c20ebfa79bef3113527fc963cec61c60f/dist-indexer.js#L20-L22 to fetch the package.json file for npm.

Start in dist-indexer.js at lines 20-22, then trace the JSON.parse call at line 119 and reproduce the promotion script against an rc build such as v0.10.44-rc.1. Done means rc builds no longer produce the JSON parse error and their npm versions are indexed successfully.