[otexplorer] Panic when accessing COLR.version

`$ cargo r /Users/drott/dev/color-fonts/build/test_glyphs-glyf_colr_1.ttf -q COLR.version`

```
Running `/Users/drott/dev/fontations/target/debug/otexplorer /Users/drott/dev/color-fonts/build/test_glyphs-glyf_colr_1.ttf -q COLR.version`
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', read-fonts/src/tables/../../generated/generated_colr.rs:275:42
```

While for example
```
$ cargo r /Users/drott/dev/color-fonts/build/test_glyphs-glyf_colr_1.ttf -q post.version
$ cargo r /Users/drott/dev/color-fonts/build/test_glyphs-glyf_colr_1.ttf -q hhea.version
```
work fine.

Reproduce the panic with the `cargo r ... -q COLR.version` command, then inspect `read-fonts/src/tables/../../generated/generated_colr.rs` around line 275 and compare it with the working `post.version` and `hhea.version` queries. Done means querying `COLR.version` no longer panics and returns a value like the other table-version queries.

Written by the indexing model from the issue text.