updatekeys command should take --input-type option into account

[julianguinard]

SOPS Version

SOPS v3.7.3, linux, amd64

Problem description

I have an encrypted test.sops.conf file that has been encrypted using the INI format

jguinard@laptop1515753:~/git/testg$ cat ~/tmp/test.sops.conf.ini|head -n 2
[default]
endpoint = ENC[AES256_GCM,data:iM+lmsnm,iv:7/S1Hay33u6Z23rUQJxeb6OicsB1a6DupKdnyR4BfEY=,tag:SMDEWIpz5TkywvmRGh9poA==,type:str]

If I try to update keys for it using the sops --input-type ini updatekeys command, the --input-type is ignored and I get the following error

jguinard@laptop1515753:~/git/testg$ sops --input-type ini updatekeys -y ~/tmp/test.sops.conf
2022/07/01 12:38:28 Syncing keys for file /home/jguinard/tmp/test.sops.conf
Error unmarshalling input json: invalid character 'd' looking for beginning of value

It seems that the command ignores the provided "ini" format and tries to handle the file as "binary"

By opposition, if I rename the file by adding the .ini extension to it and run the same command against it, the command will work

jguinard@laptop1515753:~/git/testg$ sops --input-type ini updatekeys -y ~/tmp/test.sops.conf.ini 
2022/07/01 12:38:38 Syncing keys for file /home/jguinard/tmp/test.sops.conf.ini
2022/07/01 12:38:38 File /home/jguinard/tmp/test.sops.conf.ini already up to date

Expected behavior

Using sops --input-type <format> updatekeys should take the --input-type format into account and handle the file in the specified format instead of trying to determine the format from its extension

[felixfontein]

I implemented this in #1116.