log: update to env_logger 0.10 to fix GHSA-g98v-hv3f-hcfr (tokio-rs#2740)

The package `atty`, a dependent of `env_logger` < 0.10, has a RUSTSEC advisory
raised against it (GHSA-g98v-hv3f-hcfr). This branch updates `env_logger` to
0.10 to fix this issue.
; Conflicts:
;	tracing-log/Cargo.toml

Author: maxburke

tracing-log/Cargo.toml

@@ -26,7 +26,7 @@ log-tracer = []
 tracing-core = { path = "../tracing-core", version = "0.2"}
 log = "0.4.17"
 once_cell = "1.13.0"
-env_logger = { version = "0.8.4", optional = true }
+env_logger = { version = "0.10", optional = true }
 
 [dev-dependencies]
 tracing = { path = "../tracing", version = "0.2"}