INPUT_ environment variables shouldn't be present in composite Actions

[cedws]

Bug report info

act version:            0.2.77
GOOS:                   darwin
GOARCH:                 arm64
NumCPU:                 10
Docker host:            DOCKER_HOST environment variable is not set
Sockets found:
	/var/run/docker.sock
Config files:           
	/Users/development/Library/Application Support/act/actrc:
		-P ubuntu-latest=catthehacker/ubuntu:act-latest
		-P ubuntu-22.04=catthehacker/ubuntu:act-22.04
		-P ubuntu-20.04=catthehacker/ubuntu:act-20.04
		-P ubuntu-18.04=catthehacker/ubuntu:act-18.04
Build info:
	Go version:            go1.24.2
	Module path:           github.com/nektos/act
	Main version:          v0.2.78-0.20250504121323-324bab61f056
	Main path:             github.com/nektos/act
	Main checksum:         
	Build settings:
		-buildmode:           exe
		-compiler:            gc
		CGO_ENABLED:          1
		CGO_CFLAGS:           
		CGO_CPPFLAGS:         
		CGO_CXXFLAGS:         
		CGO_LDFLAGS:          
		GOARCH:               arm64
		GOOS:                 darwin
		GOARM64:              v8.0
		vcs:                  git
		vcs.revision:         324bab61f056e7e103b142b4c2f8b3b34421d764
		vcs.time:             2025-05-04T12:13:23Z
		vcs.modified:         false
Docker Engine:
	Engine version:        27.5.1
	Engine runtime:        runc
	Cgroup version:        2
	Cgroup driver:         cgroupfs
	Storage driver:        overlay2
	Registry URI:          https://index.docker.io/v1/
	OS:                    OrbStack
	OS type:               linux
	OS version:            
	OS arch:               aarch64
	OS kernel:             6.12.15-orbstack-00304-gd0ddcf70447d
	OS CPU:                10
	OS memory:             12008 MB
	Security options:
		name=seccomp,profile=builtin
		name=cgroupns

Command used with act

act -W test.yml

Describe issue

When a composite Action is ran, the inputs are available to steps as environment variables (INPUT_*)

As per the docs, this should not be the case - composite Actions are an exception and don't have these environment variables:

If the action is written using a composite, then it will not automatically get INPUT_<VARIABLE_NAME>. With composite actions you can use inputs Accessing contextual information about workflow runs to access action inputs.

https://docs.github.com/en/actions/sharing-automations/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs

Link to GitHub repository

No response

Workflow content

name: "Test"
description: "Test"

inputs:
  test:
    description: "Test"
    default: "test"

runs:
  using: "composite"
  steps:
    - name: Test
      shell: bash
      run: |
        env

Relevant log output

| INPUT_TEST=test

Additional information

No response