Fix(Pip, Pipenv): Pipenv applies for all selections

[aoyako]

What are you trying to accomplish?

Fixes Pipenv dependency resolution for all dependency groups.
The issue I am trying to resolve: #16523 - also includes an example of a test repo with issue reproduction.

When the same dependency exists in both [packages] and [dev-packages], Dependabot parses both requirements, but PipenvRunner currently only uses the first requirement group when running pipenv upgrade.

As a result, only one section of Pipfile.lock is updated.

How will you know you've accomplished your goal?

I run Dependabot for my test repo that reproduces the issue:
bin/dry-run.rb pip aoyako/dependabot-test --dep=requests

Before: only [packages] are updated

=> bump requests from 2.30.0 to 2.34.2

    ± Pipfile.lock
    ~~~
    --- /tmp/original20261010-122141-5e7l9y	2026-10-10 07:59:51.340578009 +0000
    +++ /tmp/updated20261010-122141-pc12gq	2026-10-10 07:59:51.340578009 +0000
    @@ -1,7 +1,7 @@
     {
         "_meta": {
             "hash": {
    -            "sha256": "08b75b63f7328c20f03e6d85477337c35b16d584a6241d7894ee896f9283efab"
    +            "sha256": "7c1a614d578ea337264271b2d01159f6c9effd110600ff6466c0f7e34924fa37"
             },
             "pipfile-spec": 6,
             "requires": {},
    @@ -210,12 +210,12 @@
             },
             "requests": {
                 "hashes": [
    -                "sha256:10e94cc4f3121ee6da529d358cdaeaff2f1c409cd377dbc72b825852f2f7e294",
    -                "sha256:239d7d4458afcb28a692cdd298d87542235f4ca8d36d03a15bfc128a6559a2f4"
    +                "sha256:2a0d60c172f83ac6ab31e4554906c0f3b3588d37b5cb939b1c061f4907e278e0",
    +                "sha256:f288924cae4e29463698d6d60bc6a4da69c89185ad1e0bcc4104f584e960b9ed"
                 ],
                 "index": "pypi",
    -            "markers": "python_version >= '3.7'",
    -            "version": "==2.30.0"
    +            "markers": "python_version >= '3.10'",
    +            "version": "==2.34.2"
             },
             "urllib3": {
                 "hashes": [
    ~~~
    6 insertions (+), 6 deletions (-)

After: both [packages] and [dev-packages] are updated

=> bump requests from 2.30.0 to 2.34.2

    ± Pipfile.lock
    ~~~
    --- /tmp/original20261010-11-micd1f	2026-10-10 08:02:06.822630002 +0000
    +++ /tmp/updated20261010-11-rzsjxz	2026-10-10 08:02:06.822630002 +0000
    @@ -1,7 +1,7 @@
     {
         "_meta": {
             "hash": {
    -            "sha256": "08b75b63f7328c20f03e6d85477337c35b16d584a6241d7894ee896f9283efab"
    +            "sha256": "7c1a614d578ea337264271b2d01159f6c9effd110600ff6466c0f7e34924fa37"
             },
             "pipfile-spec": 6,
             "requires": {},
    @@ -210,12 +210,12 @@
             },
             "requests": {
                 "hashes": [
    -                "sha256:10e94cc4f3121ee6da529d358cdaeaff2f1c409cd377dbc72b825852f2f7e294",
    -                "sha256:239d7d4458afcb28a692cdd298d87542235f4ca8d36d03a15bfc128a6559a2f4"
    +                "sha256:2a0d60c172f83ac6ab31e4554906c0f3b3588d37b5cb939b1c061f4907e278e0",
    +                "sha256:f288924cae4e29463698d6d60bc6a4da69c89185ad1e0bcc4104f584e960b9ed"
                 ],
                 "index": "pypi",
    -            "markers": "python_version >= '3.7'",
    -            "version": "==2.30.0"
    +            "markers": "python_version >= '3.10'",
    +            "version": "==2.34.2"
             },
             "urllib3": {
                 "hashes": [
    @@ -423,12 +423,12 @@
             },
             "requests": {
                 "hashes": [
    -                "sha256:10e94cc4f3121ee6da529d358cdaeaff2f1c409cd377dbc72b825852f2f7e294",
    -                "sha256:239d7d4458afcb28a692cdd298d87542235f4ca8d36d03a15bfc128a6559a2f4"
    +                "sha256:2a0d60c172f83ac6ab31e4554906c0f3b3588d37b5cb939b1c061f4907e278e0",
    +                "sha256:f288924cae4e29463698d6d60bc6a4da69c89185ad1e0bcc4104f584e960b9ed"
                 ],
                 "index": "pypi",
    -            "markers": "python_version >= '3.7'",
    -            "version": "==2.30.0"
    +            "markers": "python_version >= '3.10'",
    +            "version": "==2.34.2"
             },
             "urllib3": {
                 "hashes": [
    ~~~
    10 insertions (+), 10 deletions (-)

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
  One test is already failing, it is not related to that change.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.