Replace unmaintained paste crate with pastey

[darjus]

Summary

• Replace paste dependency with pastey (RUSTSEC-2024-0436)
• Update all paste::item! invocations to pastey::paste! across src/lib.rs and src/sql_type/lob.rs
• No functional changes; inner [< >] concatenation syntax and :lower/:upper modifiers are unchanged

Test plan

• cargo build passes
• cargo test fails for unrelated tests (due to missing test schema objects (TestTempTable, TestStrings, TestDataTypes, test_vector_type, pkg_TestOutCursors) that require a SYSDBA-level setup script)

test result: FAILED. 23 passed; 13 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.54s

• cargo audit no longer flags RUSTSEC-2024-0436

cargo audit
    Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
      Loaded 949 security advisories (from /Users/dloktevi/.cargo/advisory-db)
    Updating crates.io index
    Scanning Cargo.lock for vulnerabilities (43 crate dependencies)