Remove implicit Content-Type conversion

[mary-ext]

This line of code is problematic

atcute/packages/core/client/lib/rpc.ts

Lines 147 to 157 in ed74cf0

	if (responseType) {
	if (responseType.startsWith('application/json')) {
	promise = response.json();
	} else if (responseType.startsWith('text/')) {
	promise = response.text();
	}
	}
	try {
	ret = await (promise || response.arrayBuffer().then((buffer) => new Uint8Array(buffer)));
	} catch (err) {

We should always assume XRPC to return JSON, if the lexicon specifies returning anything other than JSON, then we should make this explicit in the types.

const { data } = await rpc.get('com.atproto.sync.getBlob', {
  // this is required, must be `json`, `blob` or `bytes`
  as: 'blob',
});