pixi install --frozen is not behaving as expected when no lockfile is available

[pavelzw]

Checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

❯ pixi init
✔ Initialized project in /private/tmp/pixi-test/.
❯ pixi add python
✔ Added python 3.11.5.*
❯ ls -la
.rw-r--r--   63 pavel  3 Okt 10:39 .gitattributes
.rw-r--r--   27 pavel  3 Okt 10:39 .gitignore
drwxr-xr-x    - pavel  3 Okt 10:39 .pixi
.rw-r--r-- 7,3k pavel  3 Okt 10:39 pixi.lock
.rw-r--r--  240 pavel  3 Okt 10:39 pixi.toml
❯ rm -rf .pixi pixi.lock
❯ ls -la
.rw-r--r--  63 pavel  3 Okt 10:39 .gitattributes
.rw-r--r--  27 pavel  3 Okt 10:39 .gitignore
.rw-r--r-- 240 pavel  3 Okt 10:39 pixi.toml
❯ pixi install --frozen
✔ Project in /private/tmp/pixi-test is ready to use!
❯ ls -la
.rw-r--r--  63 pavel  3 Okt 10:39 .gitattributes
.rw-r--r--  27 pavel  3 Okt 10:39 .gitignore
.rw-r--r-- 240 pavel  3 Okt 10:39 pixi.toml
❯ pixi install --locked
  × Lockfile not up-to-date with the project

Issue description

pixi doesn't do anything when no lockfile is available.

Expected behavior

It should crash when no lockfile is available.

[ruben-arts]

Thanks! Will look at it right away!