closed stdin leads to runtime error: invalid memory address or nil pointer dereference

[aleskandro]

Describe the bug
When the stdin fd is closed in the env where yq runs, yq panics.

Version of yq: Since v4.26.1
Operating system: linux (at least)
Installed via: docker/binary

Input Yaml
data1.yml:

this: should really work

Command
The command you ran:

yq e data1.yaml <&-

Actual behavior

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x7028bb]

goroutine 1 [running]:
github.com/mikefarah/yq/v4/cmd.processStdInArgs({0xc000070700?, 0x2, 0x2})
        /home/runner/work/yq/yq/cmd/utils.go:131 +0x3b
github.com/mikefarah/yq/v4/cmd.processArgs({0xc000070700?, 0x0?, 0xc0001bdc68?})
        /home/runner/work/yq/yq/cmd/utils.go:163 +0xb5
github.com/mikefarah/yq/v4/cmd.initCommand(0x6fcaa6?, {0xc000070700, 0x2, 0x2})
        /home/runner/work/yq/yq/cmd/utils.go:22 +0x7f
github.com/mikefarah/yq/v4/cmd.evaluateSequence(0xc00011f900?, {0xc000070700, 0x2, 0x2})
        /home/runner/work/yq/yq/cmd/evalute_sequence_command.go:65 +0x9b
github.com/spf13/cobra.(*Command).execute(0xc00011f900, {0xc0000706a0, 0x2, 0x2})
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:872 +0x694
github.com/spf13/cobra.(*Command).ExecuteC(0xc00011f680)
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:990 +0x3b4
github.com/spf13/cobra.(*Command).Execute(...)
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:918
main.main()
        /home/runner/work/yq/yq/yq.go:22 +0x1f1

Expected behavior

this: should really work

Additional context
Proposed PR #1867