Do not gitignore all folders and files named publisher (#215)

This PR removes the gitignore entry for `publisher` since this
means we gitignore all folders and files named `publisher`.

My assumption is the intent for this was to just ignore binaries named
`publisher` but currently that binary is going to be located at
`tools/publisher/bin/mcp-publisher` and the **/bin pattern already
ignores all bin/ directories (taken from the build.sh).

Signed-off-by: Radoslav Dimitrov <[email protected]>
Co-authored-by: adam jones <[email protected]>

Author: rdimitrov

.gitignore

@@ -4,7 +4,6 @@ build/*
 .mcpregistry*
 **/bin
 cmd/registry/registry
-publisher
 validate-examples
 validate-schemas
 .idea/