Remove pgGraphql from setup (#7716)

## Context
This PR removes pg_graphql from the setup. It also updates the local
setup documentation accordingly.

Note: We removed local setup scripts to align with redis installation,
the setup should be much simpler since we don't rely on pg_graphql
anymore.

## Test
tested locally with docker + mac (brew) setup

packages/twenty-server/scripts/setup-db.ts

@@ -19,10 +19,6 @@ rawDataSource
       'CREATE SCHEMA IF NOT EXISTS "core"',
       'create schema "core"',
     );
-    await performQuery(
-      'CREATE EXTENSION IF NOT EXISTS "pg_graphql"',
-      'create extension pg_graphql',
-    );
 
     await performQuery(
       'CREATE EXTENSION IF NOT EXISTS "uuid-ossp"',
@@ -66,34 +62,6 @@ rawDataSource
         true,
       );
     }
-
-    await performQuery(
-      `COMMENT ON SCHEMA "core" IS '@graphql({"inflect_names": true})';`,
-      'inflect names for graphql',
-    );
-
-    await performQuery(
-      `
-      DROP FUNCTION IF EXISTS graphql;
-      CREATE FUNCTION graphql(
-        "operationName" text default null,
-        query text default null,
-        variables jsonb default null,
-        extensions jsonb default null
-      )
-        returns jsonb
-        language sql
-        as $$
-          select graphql.resolve(
-              query := query,
-              variables := coalesce(variables, '{}'),
-              "operationName" := "operationName",
-              extensions := extensions
-          );
-        $$;
-    `,
-      'create function graphql',
-    );
   })
   .catch((err) => {
     console.error('Error during Data Source initialization:', err);