Stop referencing pg_config in schema generation (pgcentralfoundation#2174)

Using `pg_config` during schema gen has been unnecessary for some time
now, and has escaped dead code warnings because our `tracing` used it.
Remove it from `generate_schema` and `copy_sql_files`.

We still need it when running `cargo pgrx schema` per se as it modifies
state to determine what features it should use.

This is an incremental step towards
pgcentralfoundation#2152 (comment)

Author: workingjubilee

cargo-pgrx/src/command/install.rs

@@ -223,7 +223,6 @@ pub(crate) fn install_extension(
         user_manifest_path,
         user_package,
         package_manifest_path,
-        pg_config,
         profile,
         is_test,
         features,
@@ -348,7 +347,6 @@ fn copy_sql_files(
     user_manifest_path: Option<impl AsRef<Path>>,
     user_package: Option<&String>,
     package_manifest_path: impl AsRef<Path>,
-    pg_config: &PgConfig,
     profile: &CargoProfile,
     is_test: bool,
     features: &clap_cargo::Features,
@@ -364,7 +362,6 @@ fn copy_sql_files(
         let dest = extdir.join(filename);
 
         crate::command::schema::generate_schema(
-            pg_config,
             user_manifest_path,
             user_package,
             &package_manifest_path,

cargo-pgrx/src/command/schema.rs

@@ -16,7 +16,7 @@ use eyre::{WrapErr, eyre};
 use object::read::macho::MachOFatFile32;
 use owo_colors::OwoColorize;
 use pgrx_pg_config::cargo::PgrxManifestExt;
-use pgrx_pg_config::{PgConfig, Pgrx, get_target_dir};
+use pgrx_pg_config::{Pgrx, get_target_dir};
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::process::Stdio;
@@ -82,7 +82,8 @@ impl CommandExecute for Schema {
             self.package.as_ref(),
             self.manifest_path.as_ref(),
         )?;
-        let (pg_config, _pg_version) = pg_config_and_version(
+        // This does meaningful mutation, unfortunately
+        let (_pg_config, _pg_version) = pg_config_and_version(
             &pgrx,
             &package_manifest,
             self.pg_version.clone(),
@@ -96,7 +97,6 @@ impl CommandExecute for Schema {
         )?;
 
         generate_schema(
-            &pg_config,
             self.manifest_path.as_ref(),
             self.package.as_ref(),
             package_manifest_path,
@@ -114,15 +114,13 @@ impl CommandExecute for Schema {
 }
 
 #[tracing::instrument(level = "error", skip_all, fields(
-    pg_version = %pg_config.version()?,
     profile = ?profile,
     test = is_test,
     path = path.as_ref().map(|path| tracing::field::display(path.as_ref().display())),
     dot,
     features = ?features.features,
 ))]
 pub(crate) fn generate_schema(
-    pg_config: &PgConfig,
     user_manifest_path: Option<impl AsRef<Path>>,
     user_package: Option<&String>,
     package_manifest_path: impl AsRef<Path>,
@@ -662,7 +660,7 @@ fn slice_arch32<'a>(data: &'a [u8], arch: &str) -> Option<&'a [u8]> {
 #[cfg(test)]
 mod tests {
     use crate::command::schema::*;
-    use pgrx_pg_config::PgConfigSelector;
+    use pgrx_pg_config::{PgConfigSelector, Pgrx};
 
     #[test]
     fn test_parse_managed_postmasters() {