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/nix-compat/src/derivation/parser.rs

@@ -23,7 +23,7 @@ pub enum Error<I> {
     #[error("premature EOF")]
     Incomplete,
     #[error("validation error: {0}")]
-    ValidationError(super::DerivationError),
+    Validation(super::DerivationError),
 }
 
 pub(crate) fn parse(i: &[u8]) -> Result<Derivation, Error<&[u8]>> {
@@ -33,7 +33,7 @@ pub(crate) fn parse(i: &[u8]) -> Result<Derivation, Error<&[u8]>> {
             debug_assert!(rest.is_empty());
 
             // invoke validate
-            derivation.validate(true).map_err(Error::ValidationError)?;
+            derivation.validate(true).map_err(Error::Validation)?;
 
             Ok(derivation)
         }