Upgrade req 0.5.10 → 0.6.1

[caioingber]

What

Bumps req from 0.5.10 to 0.6.1 and the two transitive deps it forces along: finch 0.19 → 0.22 and mint 1.7.1 → 1.9.0. Unrelated transitive deps (jason, mime, hpax, telemetry) are held at their current versions to keep the diff minimal.

Also raises the minimum Elixir version to ~> 1.15 and expands the CI matrix to cover Elixir 1.15–1.20 paired with OTP 25–29.

Why

Keeps car_req on a supported, actively maintained req release and picks up any fixes shipped in the 0.6.x line. finch 0.22 (required by req 0.6.1) requires Elixir 1.15+, so 1.14 support is dropped as part of this upgrade.

Jira ticket

N/A

Steps to Validate/Verify

N/A — covered by automated tests and code review.

Additional Notes

req 0.6.1 tightened its finch constraint to ~> 0.21 or ~> 0.22 (up from ~> 0.17), which in turn requires mint ~> 1.8. Those two upgrades are load-bearing; the others were not.

CI matrix:

Elixir	OTP
1.15	25
1.15	26
1.16	26
1.17	27
1.18	27
1.19	28
1.20	29

req changelog

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Note

Medium Risk
Upgrades the core HTTP client and connection pool stack and drops Elixir 1.14 support, which can affect downstream consumers on older toolchains even though library code is unchanged.

Overview
Upgrades the HTTP stack by bumping req from ~> 0.4 / 0.5.10 to ~> 0.6 / 0.6.1 in mix.exs, with mix.lock pulling finch 0.19 → 0.22 and mint 1.7.1 → 1.9.0 as required by req 0.6’s tighter finch constraint.

Raises the declared minimum Elixir version from ~> 1.13 to ~> 1.15 (dropping 1.14 support, aligned with finch 0.22).

CI (.github/workflows/elixir.yml) drops the deps cache step and reshapes the matrix: removes older 1.14/duplicate combos and adds sequential Elixir 1.15–1.20 paired with OTP 25–29 (e.g. 1.19/28, 1.20/29), each running mix deps.get and mix test. No application lib/ changes in this diff.

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