deps(fluent-pseudo): Bump MSRV to 1.65.0 to for fresh dependencies

This is still lower than the workspace MSRV for the other main crates
(which is 1.67.0 as of now) so 1.65.0 shouldn't be a hinderance to
anybody and allows current versions of both regex and once_cell.

Author: alerque

fluent-pseudo/Cargo.toml

@@ -6,7 +6,7 @@ a localization system designed to unleash the entire expressive power of natural
 """
 version = "0.3.2"
 edition.workspace = true
-rust-version = "1.64.0"
+rust-version = "1.65.0"
 homepage.workspace = true
 repository.workspace = true
 license.workspace = true
@@ -24,5 +24,5 @@ include = [
 ]
 
 [dependencies]
-regex = "1.9"
-once_cell = "1.20"
+regex = "1.11"
+once_cell = "1.21"