profile.d/toolbox.sh doesn't take into account TERMINFO_DIRS

**Describe the bug**
`TERMINFO_DIRS` is another way to inform tools like `tput(1)` of `terminfo(5)` entries. Because the script doesn't take it into account, you get an error on startup like `Error: terminfo entry not found for xterm-ghostty`.

**Steps how to reproduce the behaviour**
1. Store a terminfo entry in a non-default directory, like `$XDG_DATA_HOME/terminfo`
2. Enter a toolbox container

**Expected behaviour**
The script should read `TERMINFO_DIRS`.

**Actual behaviour**
`TERMINFO_DIRS` is not read.

**Output of `toolbox --version` (v0.0.90+)**
Current main branch at time of writing. See: https://github.com/containers/toolbox/blob/cb6eee85ef88a0dc8694707d29737f61fa0ac330/profile.d/toolbox.sh#L86-L101