Fix a small mistake in String.init's docs

[bbatsov]

Description

There's no "mapping" parameter. I'm guessing this was a copy/paste mistake.

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It doesn't seem I can do this.

Fixes # (issue, if applicable)

Checklist

• Test cases added

• Performance benchmarks added in case of performance changes

• Release notes entry updated:

  Please make sure to add an entry with short succinct description of the change as well as link to this pull request to the respective release notes file, if applicable.

  Release notes files:

  • If anything under src/Compiler has been changed, please make sure to make an entry in docs/release-notes/.FSharp.Compiler.Service/<version>.md, where <version> is usually "highest" one, e.g. 42.8.200
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  • More inlines for Result module. (PR #16106)
  • Correctly handle assembly imports with public key token of 0 length. (Issue #16359, PR #16363)
    *while! (Language suggestion #1038, PR #14238)

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[github-actions]

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cc @dotnet/fsharp-team-msft

[T-Gro]

Thanks for spotting this. This was likely a copy-paste mistake or a refactoring not applied to comment.
I have added the label to skip mandatory release notes.

[psfinaki]

Thanks!