bug: Does not find executable when ASDF_TOOL_VERSIONS_FILENAME is set

[alator21]

Describe the Bug

When the variable ASDF_TOOL_VERSIONS_FILENAME is set, it can't find the executable. If I unset this variable, it finds it just fine.

Steps to Reproduce

1. Install asdf v.0.18.0(revision 2114f1e)
2. set ASDF_TOOL_VERSIONS_FILENAME to something other than the default (ASDF_TOOL_VERSIONS_FILENAME= ~/.config/asdf/tool-versions)
3. Add a plugin(asdf plugin add bun)
4. Install a version(asdf install bun v1.3.0)
5. Set the version on the tool-versions(bun v1.3.0)
6. Try to access "bun"
7. Error ("No version is set for command bun \n Consider adding one of the following versions in your config file at /home/alator21/.tool-versions \n bun v1.3.0")
8. unset ASDF_TOOL_VERSIONS_FILENAME
9. Try to access "bun"
10. Works

Expected Behaviour

Find the executable

Actual Behaviour

Can't find the executable

Environment

OS:
Linux alarm 6.16.8-asahi-1-2-ARCH #1 SMP PREEMPT_DYNAMIC Mon, 13 Oct 2025 10:51:07 +0000 aarch64 GNU/Linux

SHELL:
zsh 5.9 (aarch64-unknown-linux-gnu)

BASH VERSION:
5.3.3(1)-release

ASDF VERSION:
v0.18.0 (revision 2114f1e)

ASDF INTERNAL VARIABLES:
ASDF_TOOL_VERSIONS_FILENAME=/home/alator/.config/asdf/tool-versions
ASDF_DATA_DIR=/home/alator/.asdf
ASDF_CONFIG_FILE=/home/alator/.asdfrc

ASDF INSTALLED PLUGINS:
bun        https://github.com/cometkim/asdf-bun.git
           804d9603c473ea616fa078f851fa8380246e2c7a
java       https://github.com/halcyon/asdf-java.git
           4b896be72cc1b3eff330d0921e85be2e50989fbd
lazydocker https://github.com/comdotlinux/asdf-lazydocker.git
           abb6f7124e7b75596bbe9b9bd21c983cca5bb578
nodejs     https://github.com/asdf-vm/asdf-nodejs.git
           90b8ecaa556916daba983a7b01869a9ea682f285
python     https://github.com/danhper/asdf-python.git
           d4caa7d4832313b4c141ee0ceca4118747147e89
rust       https://github.com/asdf-community/asdf-rust.git
           bb9de4503b55fd290fcc95f55df1b439d4d1513c

asdf plugins affected (if relevant)

No response