`solver.min-release-age-exclude-source` documented incorrectly

Issue Kind

Error in existing documentation

Existing Link

https://python-poetry.org/docs/configuration#solvermin-release-age-exclude-source

Description

The documentation states that the the configuration is "A comma-separated list of source names or URLs", which is true if provided as an env-var, but if set in poetry.toml, the configuration is actually parsed directly as a list (more accurately, as a set)

# poetry.toml
[solver]
min-release-age = 7
min-release-age-exclude-source = "myrepo"  # WRONG: will be treated as "m,y,r,e,p,o"

# poetry.toml
[solver]
min-release-age = 7
min-release-age-exclude-source = ["myrepo"]  # CORRECT