convert from serde-yaml to serde-saphyr

[clux]

carrying on from #1848

1. mostly search and replace crate name on docs/examples.
2. some changes in the kubectl example because multidoc parsing is easier/different.
3. boxing large serde-saphyr::Error to avoid clippy warnings

The one new error (for when we have an invalid kubeconfig) now looks better. Here's some saphyr output when i added a dash too many.

cargo run --example=kubectl get deployment -A
   Compiling kube-client v3.1.0 (/home/clux/kube/kube/kube-client)
   Compiling kube-runtime v3.1.0 (/home/clux/kube/kube/kube-runtime)
   Compiling kube v3.1.0 (/home/clux/kube/kube/kube)
   Compiling kube-examples v3.1.0 (/home/clux/kube/kube/examples)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.41s
     Running `/home/clux/kube/kube/target/debug/examples/kubectl get deployment -A`
Error: failed to parse kubeconfig YAML: error: line 3 column 3: unexpected event: expected mapping start
 --> <input>:3:3
  |
1 | apiVersion: v1
2 | clusters:
3 | - - cluster:
  |   ^ unexpected event: expected mapping start
4 |     certificate-authority-data: X…
  |

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.5%. Comparing base (a626bd4) to head (7c2573e).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1975     +/-   ##
=======================================
+ Coverage   76.5%   76.5%   +0.1%     
=======================================
  Files         89      89             
  Lines       8590    8585      -5     
=======================================
- Hits        6564    6563      -1     
+ Misses      2026    2022      -4     

Files with missing lines	Coverage Δ
kube-client/src/client/auth/mod.rs	57.4% <100.0%> (ø)
kube-client/src/config/file_config.rs	80.2% <100.0%> (+0.4%)	⬆️
kube-client/src/config/mod.rs	54.7% <ø> (ø)
kube-core/src/crd.rs	83.0% <100.0%> (ø)
kube-core/src/gvk.rs	73.8% <100.0%> (ø)
kube-derive/src/lib.rs	0.0% <ø> (ø)
kube-runtime/src/wait.rs	94.8% <100.0%> (ø)

... and 2 files with indirect coverage changes

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