Delete v3 and v4 configuration tests in favor of ndc-snapshot-metadat…

…a tests (#527)

### What

The v3 and v4 configuration tests are a bit redundant because we have
the ndc-snapshot-metadata tests. This PR removes them, introduces a
snapshot for the current v4-config, and deletes the schema.json in each
dir because they are also not used in favor of `static/schema.json`.

crates/configuration/Cargo.toml

@@ -24,5 +24,4 @@ tokio = { workspace = true, features = ["full"] }
 tracing = { workspace = true }
 
 [dev-dependencies]
-insta = { workspace = true, features = ["json"] }
 jsonschema = { workspace = true }

crates/configuration/src/version3/mod.rs

@@ -25,9 +25,6 @@ use crate::error::{
 use crate::values::{ConnectionUri, Secret};
 use crate::VersionTag;
 
-#[cfg(test)]
-mod tests;
-
 const CONFIGURATION_FILENAME: &str = "configuration.json";
 const CONFIGURATION_JSONSCHEMA_FILENAME: &str = "schema.json";
 const CONFIGURATION_QUERY: &str = include_str!("version3.sql");