VS Code for Mac: composer.json schema validation fails; URL incorrect

[wp4nuv]

Issue Type: Bug

When creating a new composer.json file, the JSON extension fails to validate with the following message:
{
"resource": "/Users/pedro/Projects/sql-updates/composer.json",
"owner": "generated_diagnostic_collection_name#0",
"code": "768",
"severity": 4,
"message": "Problems loading reference 'http://json.schemastore.org/composer': Unable to load schema from 'http://json.schemastore.org/composer': Request vscode/content failed unexpectedly without providing any details.",
"startLineNumber": 1,
"startColumn": 1,
"endLineNumber": 1,
"endColumn": 2
}
Navigating to that URL directly shows the following error:
"The resource you are looking for has been removed, had its name changed, or is temporarily unavailable."

The schema validates correctly per "composer validate" command.

VS Code version: Code 1.57.1 (Universal) (507ce72, 2021-06-17T13:28:32.912Z)
OS version: Darwin x64 19.6.0
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-3820QM CPU @ 2.70GHz (8 x 2700)
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	16.00GB (1.89GB free)
Process Argv	--crash-reporter-id fa700cc6-3cb1-4c7a-a5df-dc68ab6ad5eb
Screen Reader	no
VM	0%

Extensions (16)

Extension	Author (truncated)	Version
phptools-vscode	DEV	1.4.6762
gitlens	eam	11.5.1
vscode-test-explorer	hbe	2.20.4
composer	ika	0.7.1
syntax-project-pbxproj	mar	0.1.3
file-downloader	min	1.0.11
mindaro	min	1.0.120210615
vscode-docker	ms-	1.13.0
vscode-kubernetes-tools	ms-	1.3.3
python	ms-	2021.6.944021595
vscode-pylance	ms-	2021.6.2
jupyter	ms-	2021.6.999406279
remote-containers	ms-	0.183.0
cpptools	ms-	1.4.1
test-adapter-converter	ms-	0.0.10
vscode-yaml	red	0.20.0

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[aeschli]

The schema URL comes from the composer extension. I created ikappas/vscode-composer#19