Do not prepend dataDir option with current directory string

[scorbajio]

Currently, if a user wants to use a mounted drive such as /media/user/ExternalDrive/data for the dataDir option of the helper scripts, the setup will fail with an error.

To recreate, run:

./setup.sh --network holesky --dataDir `/media/user/ExternalDrive/data` --elClient ethereumjs

You should see output similar to this:

 ✖ Error: ENOENT: no such file or directory, open '/data/jwtsecret'
    at Object.readFileUtf8 (node:internal/fs/sync:25:18)
    at Object.readFileSync (node:fs:441:19)
    at Module.parseArgs (file:///usr/app/packages/cli/src/options/beaconNodeOptions/eth1.ts:28:32)
    at parseBeaconNodeArgs (file:///usr/app/packages/cli/src/options/beaconNodeOptions/index.ts:30:16)
    at beaconHandlerInit (file:///usr/app/packages/cli/src/cmds/beacon/handler.ts:163:51)
    at Object.beaconHandler [as handler] (file:///usr/app/packages/cli/src/cmds/beacon/handler.ts:36:90)
    at file:///usr/app/packages/cli/node_modules/yargs/build/lib/command.js:206:54
    at maybeAsyncResult (file:///usr/app/packages/cli/node_modules/yargs/build/lib/utils/maybe-async-result.js:9:15)
    at CommandInstance.handleValidationAndGetResult (file:///usr/app/packages/cli/node_modules/yargs/build/lib/command.js:205:25)
    at CommandInstance.applyMiddlewareAndGetResult (file:///usr/app/packages/cli/node_modules/yargs/build/lib/command.js:245:20)

This error results from docker failing to map a non-existant local path to the program container:

docker run --rm --name holesky-ethereumjs --network host -v /home/user/code/lodestar-quickstart//media/user/ExternalDrive/data:/data

This happens because the current directory string is being prepended to the dataDir option that the user has passed in. This change removes the prepended string so that the user can pass in absolute paths, as well.

[CLAassistant]

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