compression - How to ignore files

How can I add files/paths to ignore?

Since the compression works on the output directory---not on the input-to-output cascade eleventy performs---it seems to be oblivious to paths added via `eleventyConfig.ignores.add`. For example, if I have a custom route leading to a file that doesn't exist on my local machine:

```js
...

...
```

The compression plugin detects the path and tries to compress it:

```bash
10:13:21 AM -> Icons: Start to compress "docs/_vercel/insights/script.js" file 🆙
10:13:21 AM -> Icons: Error: ENOENT: no such file or directory, open '/Users/mpiekenbrock/peekxc.github.io/docs/_vercel/speed-insights/script.js'
Error: ENOENT: no such file or directory, open '/Users/mpiekenbrock/peekxc.github.io/docs/_vercel/speed-insights/script.js'
at async open (node:internal/fs/promises:641:25)
at async Object.readFile (node:internal/fs/promises:1254:14)
at async w (/Users/mpiekenbrock/peekxc.github.io/node_modules/eleventy-plugin-compress/index.js:1:1480)
at async Promise.all (index 4)
at async Promise.all (index 0)
at async A (/Users/mpiekenbrock/peekxc.github.io/node_modules/eleventy-plugin-compress/index.js:1:2424)
at async Object. (/Users/mpiekenbrock/peekxc.github.io/node_modules/eleventy-plugin-compress/index.js:1:2947)
at async Template.runTransforms (/Users/mpiekenbrock/.nvm/versions/node/v18.1.0/lib/node_modules/@11ty/eleventy/src/Template.js:514:15)
at async Template.renderPageEntry (/Users/mpiekenbrock/.nvm/versions/node/v18.1.0/lib/node_modules/@11ty/eleventy/src/Template.js:799:15)
at async /Users/mpiekenbrock/.nvm/versions/node/v18.1.0/lib/node_modules/@11ty/eleventy/src/Template.js:822:21 💥
```

But there is no such file, so this just floods the output with errors.

Edit: seems related if not identical to #8

Reproduce the failure with an Eleventy custom route and an ignore added through eleventyConfig.ignores.add. Start from node_modules/eleventy-plugin-compress/index.js and the Eleventy Template transform frames in the trace; done means ignored or nonexistent generated paths no longer trigger compression errors, with behavior checked against the related #8 report.

Written by the indexing model from the issue text.