fix monaco-graphql bug with _cacheSchemas()

[acao]

Introduced this slight bug with major impact to monaco-graphql last night whilst moving things around.

Actual Behavior:

No language features appear. Schema request completes but the editor doesn't appear to load features.

Expected behavior:

Language features should appear

Followup:
Need a basic jest and/or cypress suite for monaco-graphql asap! Jest looks difficult with monaco-editor from what I've read

[changeset-bot]

🦋 Changeset detected

Latest commit: 3ef32d1

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
monaco-graphql	Patch

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[github-actions]

The latest changes of this PR are available as canary in npm (based on the declared changesets):

[email protected]

[codecov]

Codecov Report

Merging #2105 (3ef32d1) into main (2d91916) will decrease coverage by 1.03%.
The diff coverage is 76.54%.

@@            Coverage Diff             @@
##             main    #2105      +/-   ##
==========================================
- Coverage   65.70%   64.66%   -1.04%     
==========================================
  Files          85       77       -8     
  Lines        5106     5168      +62     
  Branches     1631     1641      +10     
==========================================
- Hits         3355     3342      -13     
- Misses       1747     1822      +75     
  Partials        4        4              

Impacted Files	Coverage Δ
packages/codemirror-graphql/src/hint.ts	94.73% <ø> (ø)
packages/codemirror-graphql/src/lint.ts	100.00% <ø> (ø)
packages/codemirror-graphql/src/results/mode.ts	47.05% <ø> (ø)
...kages/codemirror-graphql/src/utils/forEachState.ts	100.00% <ø> (ø)
...ckages/codemirror-graphql/src/utils/mode-indent.ts	0.00% <0.00%> (ø)
packages/codemirror-graphql/src/variables/hint.ts	89.70% <ø> (ø)
packages/codemirror-graphql/src/variables/mode.ts	79.48% <ø> (ø)
packages/graphiql/src/components/QueryEditor.tsx	63.96% <ø> (ø)
packages/graphiql/src/utility/fillLeafs.ts	5.33% <ø> (ø)
...kages/graphiql/src/utility/introspectionQueries.ts	100.00% <ø> (ø)
... and 56 more

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[github-actions]

🚀 Deployed on https://61b0a7570f8bf00b4128d6fb--monaco-graphql.netlify.app

[github-actions]

🚀 Deployed on https://61b0a742c98f300090821ddc--graphiql-webpack-example.netlify.app

[github-actions]

🚀 Deployed on https://61b0a74223603a0cd6220c09--graphiql-test.netlify.app