rust-format: update rustfmt version
This hasn't been updated in a while, and since we're updating the MSRV to
1.48.0, we might as well do this.
Differential Revision: https://phab.mercurial-scm.org/D11733
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false
IncludeCategories:
- Regex: '^<'
Priority: 1
- Regex: '^"'
Priority: 2