Duplicate call for _cleanupLookupMap

[LMestre14]

In our project I've been doing some investigation on where we could improve in terms of performance (both on our implementation and on the framework itself).
After adding some logs to understand the framework's behaviour I saw that when we are reaching the limit of the memory pressure, the garbage collection function is called, and one of the things I noticed is that we have a duplicated call of the function _cleanupLookupMap when we call the gc function in the TextureManager.

src/tree/TextureManager.mjs

    gc() {
        this.freeUnusedTextureSources();
        this._cleanupLookupMap(); // we are calling the function here
    }
    
    freeUnusedTextureSources() {
        let remainingTextureSources = [];
        for (let i = 0, n = this._uploadedTextureSources.length; i < n; i++) {
            let ts = this._uploadedTextureSources[i];
            if (ts.allowCleanup()) {
                this._freeManagedTextureSource(ts);
            } else {
                remainingTextureSources.push(ts);
            }
        }

        this._uploadedTextureSources = remainingTextureSources;

        this._cleanupLookupMap(); // and we already call it here
    }