fix: remove b option from update.sh help

[MikeMcC399]

Refs: #2412

Description

In the update.sh script:

• remove the unavailable -b option from help text

Motivation and Context

The option -b is no longer available.

PR #1339 in Oct 2020 removed the b option from the list of examples, and from getopts. It missed removing it from the help list under the OPTIONS heading, leaving the help text in an inconsistent state.

Testing Details

Execute ./update.sh -h and confirm that -b no longer appears in the OPTIONS list.

Example Output

$ ./update.sh -h

  Update the node docker images.

  Usage:
    ./update.sh [-s] [MAJOR_VERSION(S)] [VARIANT(S)]

  Examples:
    - update.sh                      # Update all images
    - update.sh -s                   # Update all images, skip updating Alpine and Yarn
    - update.sh 8,10                 # Update all variants of version 8 and 10
    - update.sh -s 8                 # Update version 8 and variants, skip updating Alpine and Yarn
    - update.sh 8 alpine             # Update only alpine's variants for version 8
    - update.sh -s 8 bullseye        # Update only bullseye variant for version 8, skip updating Alpine and Yarn
    - update.sh . alpine             # Update the alpine variant for all versions

  OPTIONS:
    -s Security update; skip updating the yarn and alpine versions.
    -h Show this message

Types of changes

• Documentation
• Version change (Update, remove or add more Node.js versions)
• Variant change (Update, remove or add more variants, or versions of variants)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Other (none of the above)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• All new and existing tests passed.