Update capnpc requirement from 0.14.2 to 0.15.2 in /gst-depth-meta-rs

Updates the requirements on capnpc to permit the latest version.

Commits

• 37a7b49 prepare for capnpc-v0.15.2 release
• 117bc97 regenerate code to eliminate clippy warnings
• eb94067 replace -> take
• 20b4986 Merge pull request #360 from zh-jq/master
• d953b4a capnpc codegen: fix clippy warning
• 6d120a0 prepare for capnpc-v0.15.1 release
• e2654ae blog: update docs link, and add link for 'munging'
• 9dc826e Merge pull request #358 from danieleades/clippy/let-else
• b471a90 Merge pull request #357 from danieleades/clippy-msrv
• 697ad9a use 'let/else' syntax
• Additional commits viewable in compare view