integrations: Remove unused logos and screenshots.

Remove images that are no longer referenced in the integration docs.

This is in preparation for adding a test that checks image links in
integration docs. This commit is required to make the test pass.

static/images/integrations/logos/solano.svg

@@ -1 +0,0 @@
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static/images/integrations/logos/yo.svg

@@ -1 +0,0 @@
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