build(deps): update capnpc requirement from 0.14.2 to 0.15.1 in /gst-depth-meta-rs

Updates the requirements on capnpc to permit the latest version.

Commits

• 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
• 022d10c configure the clippy MSRV
• 59efe94 Merge pull request #343 from danieleades/clippy/general
• b7abb11 update toplevel README docs link to docs.rs
• e6e1611 update README docs links to docs.rs
• beb8360 update Cargo.toml doc links to docs.rs
• Additional commits viewable in compare view