chore(3p/sources): Bump channels & overlays

- Adjust to ecl 23.9.9 release

- Regenerate go protos after protoc-gen-go update

- Drop dhall fork which hasn't kept up with 1.42.*

- Address new clippy warnings:

  - Variant naming of Error::ValidationError
  - Simplify .try_into().unwrap()
  - Drop unnecessary identity function
  - Test module must be last in file
  - Drop unused `pub use`

- Update agenix to 0.15.0. Current master has a installCheckPhase that
  doesn't work with C++ Nix 2.3.*:
  a23aa271be (commitcomment-137185861)

Change-Id: Ic29eef20d6fd1362ce1031364a5ca6b4edf195bd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10615
Reviewed-by: aspen <root@gws.fyi>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>

tvix/eval/src/value/attrs/tests.rs

@@ -78,11 +78,7 @@ fn test_kv_attrs_iter() {
     )
     .expect("constructing K/V pair attrs should succeed");
 
-    let mut iter = kv_attrs
-        .iter()
-        .collect::<Vec<_>>()
-        .into_iter()
-        .map(|(k, v)| (k, v));
+    let mut iter = kv_attrs.iter().collect::<Vec<_>>().into_iter();
     let (k, v) = iter.next().unwrap();
     assert!(k == *NAME_REF);
     assert!(v.to_str().unwrap() == meaning_val.to_str().unwrap());