Replace `dotenv` with `dotenvy` #3701

Job	Run time
Rustfmt	28s
Clippy	1m 51s
Examples Matrix	3s
Init	4s
Unit Test	5m 38s
Compile MySQL (actix, native-tls)	5m 10s
Compile MySQL (actix, rustls)	5m 35s
CLI	0s
Compile PostgreSQL (tokio, native-tls)	6m 39s
Compile PostgreSQL (tokio, rustls)	7m 8s
Compile SQLite (async-std, native-tls)	5m 58s
Compile SQLite (async-std, rustls)	5m 43s
Examples (examples/rocket_example)	5m 57s
Examples (examples/jsonrpsee_example)	4m 9s
Examples (examples/axum_example)	3m 33s
Examples (examples/graphql_example)	4m 41s
Examples (examples/actix3_example)	4m 38s
Examples (examples/tonic_example)	5m 2s
Examples (examples/actix_example)	4m 0s
Examples (examples/basic)	1m 39s
Examples (examples/rocket_okapi_example)	5m 17s
Examples (examples/seaography_example)	4m 7s
Examples (examples/poem_example)	4m 6s
Examples (examples/salvo_example)	4m 36s
Issues Matrix	0s
Issues	0s
MySQL (8, actix, native-tls)	8m 34s
MySQL (5.7, actix, native-tls)	7m 53s
MariaDB (10.6, actix, native-tls)	5m 19s
SQLite (async-std, native-tls)	6m 15s
SQLite (async-std, rustls)	5m 37s
Postgres (14.4, tokio, native-tls)	9m 43s
	2h 19m 23s

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