Update outdated dependencies

[lovasoa]

Summary

• update git2, odbc-api, and sha1 dependency lines
• migrate ODBC buffering code to odbc-api 28 ColumnarDynBuffer APIs
• keep MySQL RSA OAEP compatibility isolated to sha1 0.10 while the normal SHA-1 path uses sha1 0.11

Validation

• cargo check -p sqlx-core-oldapi --no-default-features --features postgres,mysql,sqlite,odbc,git2,rustls,all-types,offline
• cargo test -p sqlx-core-oldapi --lib --no-default-features --features postgres,mysql,sqlite,odbc,git2,rustls,all-types,offline