build(deps): bump itoa from 1.0.9 to 1.0.18

[dependabot]

Bumps itoa from 1.0.9 to 1.0.18.

Release notes

Sourced from itoa's releases.

1.0.18

• Simplify pointer usage in Buffer::format method (#67, thanks @​xtqqczze)
• Optimize 128-bit integer formatting (#68, thanks @​jhpratt)

1.0.17

• Documentation improvements

1.0.16

• Synchronize algorithm improvements from libcore (#65)

1.0.15

• Documentation improvements

1.0.14

• Work around bad IDE suggestion (#56)

1.0.13

• Code cleanup (#48, #49, #50, #51, #52, #53, #54, #55)

1.0.12

• Add itoa::Integer::MAX_STR_LEN associated constant (#45, thanks @​SUPERCILEX)

1.0.11

• More granular unsafe blocks (#42, thanks @​anforowicz)

1.0.10

• Improve test coverage (#41, thanks @​CXWorks)

Commits

• af77385 Release 1.0.18
• 73a7c03 Merge pull request #68 from jhpratt/master
• 7b4c86b Optimize 128-bit integer formatting
• 0d8a489 Fill in pointer cast type
• e693c49 Merge pull request #67 from xtqqczze/as_mut_ptr
• 29b3410 Simplify pointer usage in Buffer::format method
• bbf077f Switch to 9975WX benchmark data
• 65bc721 Delete old chart code
• 21d6109 Release 1.0.17
• 55c15a1 Use performance chart from itoa-benchmark
• Additional commits viewable in compare view