fix(headers): silently skip empty header names instead of throwing

[rkdfx]

Summary

AxiosHeaders.setHeader threw Error: header name must be a non-empty string whenever an input source contained an empty key. React Native 0.80+ on Android emits such an entry from response.headers, which made every response throw and crash user code. Switch to a silent skip, mirroring parseHeaders -

axios/lib/helpers/parseHeaders.js

Lines 53 to 55 in 847d89b

	if (!key || (parsed[key] && ignoreDuplicateOf[key])) {
	return;
	}

Linked issue

Closes #6959

Changes

• lib/core/AxiosHeaders.js: replace the empty-name throw in
  setHeader with an early return.
• tests/unit/axiosHeaders.test.js: cover empty-name handling across
  all three input shapes.

Checklist

• Tests added or updated (or N/A with reason)
• Docs / types updated if public API changed (index.d.ts and index.d.cts)
• No breaking changes (or called out explicitly above)

---

Summary by cubic

Silently skip empty or whitespace-only header names in AxiosHeaders.setHeader to prevent crashes when platforms emit empty keys (e.g., React Native 0.80+ on Android). Mirrors parseHeaders behavior and fixes #6959.

Description

• Summary of changes: Replace the throw on empty/whitespace-only header names in AxiosHeaders.setHeader with an early return (no-op).
• Reasoning: React Native Android can emit an empty-name header, which previously caused responses to throw and crash user code.
• Additional context: Matches parseHeaders; applies to string keys, plain objects, and Map inputs.

Docs

• Update /docs/ to note that empty or whitespace-only header names are ignored across string/object/Map inputs, matching parseHeaders.

Testing

• Added unit tests in tests/unit/axiosHeaders.test.js covering empty and whitespace-only names for string, object, and Map inputs.
• Asserts no throws, valid headers remain, and object length is 2.

Semantic version impact

• Patch: bug fix with no API changes; removes unexpected throws without breaking valid usage.

^{Written for commit a63294d. Summary will update on new commits. Review in cubic}

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

[jasonsaayman]

Two small suggestions are inline; both are non-blocking on their own but flag together. Nice fix overall: leaf-level placement is the right call, and the test matrix across string/object/Map is exactly what this needs.

[joe345-str]

merge please