fix persisting headers in tab state

[thomasheyenbrock]

The logic for persisting headers in tabs was exactly switched, i.e. we stripped headers when shouldPersistHeaders was true. This also caused GraphiQL to open duplicate tabs when the headers prop was used: #2380

[changeset-bot]

🦋 Changeset detected

Latest commit: 3606924

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

This PR includes changesets to release 1 package

Name	Type
graphiql	Patch

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[codecov]

Codecov Report

Merging #2418 (3606924) into main (2d91916) will increase coverage by 2.45%.
The diff coverage is 71.52%.

@@            Coverage Diff             @@
##             main    #2418      +/-   ##
==========================================
+ Coverage   65.70%   68.16%   +2.45%     
==========================================
  Files          85       75      -10     
  Lines        5106     4702     -404     
  Branches     1631     1547      -84     
==========================================
- Hits         3355     3205     -150     
+ Misses       1747     1493     -254     
  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)
packages/codemirror-graphql/src/utils/hintList.ts	95.65% <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-react/src/editor/whitespace.ts	100.00% <ø> (ø)
packages/graphiql-toolkit/src/storage/query.ts	36.73% <ø> (ø)
... and 91 more

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