clippy warning fix

[milyin]

Fix for new clippy warning

> cargo +stable clippy --all-targets -- --deny warnings

   Compiling zenoh-macros v0.11.0-dev (/home/milyin/ZS/zenoh/commons/zenoh-macros)
error: file opened with `create`, but `truncate` behavior not defined
  --> commons/zenoh-macros/build.rs:25:10
   |
25 |         .create(true)
   |          ^^^^^^^^^^^^- help: add: `.truncate(true)`
   |
   = help: if you intend to overwrite an existing file entirely, call `.truncate(true)`
   = help: if you instead know that you may want to keep some parts of the old file, call `.truncate(false)`

[eclipse-zenoh-bot]

@milyin If this pull request contains a bugfix or a new feature, then please consider using Closes #ISSUE-NUMBER syntax to link it to an issue.