Local modules made with nf-core modules create use prefix variable in stub when no meta is selected

Description of the bug

Problem is actually the use of prefix in stub when no meta is selected.

When creating a local module with nf-core modules create in a pipeline, the def prefix = task.ext.prefix ?: meta.id is missing, and the variable is referenced at least in the stub section.

Command used and terminal output

$ nf-core modules create fcsgx/fetchdb # resulted in the following file

// TODO nf-core: If in doubt look at other nf-core/modules to see how we are doing things! :)
//               https://github.com/nf-core/modules/tree/master/modules/nf-core/
//               You can also ask for help via your pull request or on the #modules channel on the nf-core Slack workspace:
//               https://nf-co.re/join
// TODO nf-core: A module file SHOULD only define input and output files as command-line parameters.
//               All other parameters MUST be provided using the "task.ext" directive, see here:
//               https://www.nextflow.io/docs/latest/process.html#ext
//               where "task.ext" is a string.
//               Any parameters that need to be evaluated in the context of a particular sample
//               e.g. single-end/paired-end data MUST also be defined and evaluated appropriately.
// TODO nf-core: Software that can be piped together SHOULD be added to separate module files
//               unless there is a run-time, storage advantage in implementing in this way
//               e.g. it's ok to have a single module for bwa to output BAM instead of SAM:
//                 bwa mem | samtools view -B -T ref.fasta
// TODO nf-core: Optional inputs are not currently supported by Nextflow. However, using an empty
//               list (`[]`) instead of a file can be used to work around this issue.

process FCSGX_FETCHDB {
    tag '$bam'
    label 'process_single'

    // TODO nf-core: List required Conda package(s).
    //               Software MUST be pinned to channel (i.e. "bioconda"), version (i.e. "1.10").
    //               For Conda, the build (i.e. "h9402c20_2") must be EXCLUDED to support installation on different operating systems.
    // TODO nf-core: See section in main README for further information regarding finding and adding container addresses to the section below.
    conda "YOUR-TOOL-HERE"
    container "${ workflow.containerEngine == 'singularity' && !task.ext.singularity_pull_docker_container ?
        'https://depot.galaxyproject.org/singularity/YOUR-TOOL-HERE':
        'biocontainers/YOUR-TOOL-HERE' }"

    input:
    // TODO nf-core: Where applicable all sample-specific information e.g. "id", "single_end", "read_group"
    //               MUST be provided as an input via a Groovy Map called "meta".
    //               This information may not be required in some instances e.g. indexing reference genome files:
    //               https://github.com/nf-core/modules/blob/master/modules/nf-core/bwa/index/main.nf
    // TODO nf-core: Where applicable please provide/convert compressed files as input/output
    //               e.g. "*.fastq.gz" and NOT "*.fastq", "*.bam" and NOT "*.sam" etc.
    path bam

    output:
    // TODO nf-core: Named file extensions MUST be emitted for ALL output channels
    path "*.bam", emit: bam
    // TODO nf-core: List additional required output channels/values here
    path "versions.yml"           , emit: versions

    when:
    task.ext.when == null || task.ext.when

    script:
    def args = task.ext.args ?: ''
    
    // TODO nf-core: Where possible, a command MUST be provided to obtain the version number of the software e.g. 1.10
    //               If the software is unable to output a version number on the command-line then it can be manually specified
    //               e.g. https://github.com/nf-core/modules/blob/master/modules/nf-core/homer/annotatepeaks/main.nf
    //               Each software used MUST provide the software name and version number in the YAML version file (versions.yml)
    // TODO nf-core: It MUST be possible to pass additional parameters to the tool as a command-line string via the "task.ext.args" directive
    // TODO nf-core: If the tool supports multi-threading then you MUST provide the appropriate parameter
    //               using the Nextflow "task" variable e.g. "--threads $task.cpus"
    // TODO nf-core: Please replace the example samtools command below with your module's command
    // TODO nf-core: Please indent the command appropriately (4 spaces!!) to help with readability ;)
    """
    samtools \\
        sort \\
        $args \\
        -@ $task.cpus \\
        $bam

    cat <<-END_VERSIONS > versions.yml
    "${task.process}":
        : \$(echo \$(samtools --version 2>&1) | sed 's/^.*samtools //; s/Using.*\$//' ))
    END_VERSIONS
    """

    stub:
    def args = task.ext.args ?: ''
    
    // TODO nf-core: A stub section should mimic the execution of the original module as best as possible
    //               Have a look at the following examples:
    //               Simple example: https://github.com/nf-core/modules/blob/818474a292b4860ae8ff88e149fbcda68814114d/modules/nf-core/bcftools/annotate/main.nf#L47-L63
    //               Complex example: https://github.com/nf-core/modules/blob/818474a292b4860ae8ff88e149fbcda68814114d/modules/nf-core/bedtools/split/main.nf#L38-L54
    """
    touch ${prefix}.bam

    cat <<-END_VERSIONS > versions.yml
    "${task.process}":
        : \$(echo \$(samtools --version 2>&1) | sed 's/^.*samtools //; s/Using.*\$//' ))
    END_VERSIONS
    """
}

System information

nf-core/tools version 2.10
OS: macOS
Python 3.11.5

Reproduce the issue with nf-core modules create fcsgx/fetchdb using nf-core/tools 2.10, then trace the module template used by the modules create command. Check how the generated script and stub define or reference prefix; done means a newly generated local module no longer references an undefined variable and its relevant tests pass.