fix: default variable assignment and tar command syntax

[mdqst]

TITLE

Description

I’ve corrected two issues in the script:

1. The syntax for setting the default value for the NODE_EXPORTER_DIR variable was wrong. The corrected version now properly uses :- for default assignment in Bash:

   NODE_EXPORTER_DIR="${NODE_EXPORTER_DIR:-"$BASE_DIR/.node_exporter"}"

   This ensures that if NODE_EXPORTER_DIR isn’t set, it defaults to $BASE_DIR/.node_exporter.

2. Fixed the incorrect order of flags in the tar command. The -z flag for gzip compression should follow -x and precede -v. The corrected command is:

   if tar -xvzf $FILE; then

Both changes ensure the script runs without errors in these areas.

Type of change

Please delete options that are not relevant.

• Optimization

Checklist

• “Hotfix” to testnet, everything else to staging
• Linked to Github Issue
• This change depends on code or research by an external entity
  • Acknowledgements were updated to give credit
• Unit tests added
• This change requires new documentation.
  • Documentation has been added/updated.
• This change is an Optimization
  • Benchmarks added/run
• Has a known issue
  • Link to the open issue addressing it
• If your PR changes the Operator compatibility (Ex: Upgrade prover versions)
  • This PR adds compatibility for operator for both versions and do not change batcher/docs/examples
  • This PR updates batcher and docs/examples to the newer version. This requires the operator are already updated to be compatible