PostgreSQL connectors: remove duplicate record_id field in sample schema (#431)

Author: Paul-Cornell

snippets/general-shared-text/postgresql.mdx

@@ -83,7 +83,6 @@ import AllowIPAddressRanges from '/snippets/general-shared-text/ip-address-range
         id UUID PRIMARY KEY,
         record_id VARCHAR,
         element_id VARCHAR,
-        record_id TEXT,
         text TEXT,
         embeddings DECIMAL [],
         parent_id VARCHAR,
@@ -100,7 +99,6 @@ import AllowIPAddressRanges from '/snippets/general-shared-text/ip-address-range
         id UUID PRIMARY KEY,
         record_id VARCHAR,
         element_id VARCHAR,
-        record_id TEXT,
         text TEXT,
         embeddings vector(3072),
         parent_id VARCHAR,