Add maxperf build profile (#3608)

## Proposed Changes

Add a new Cargo compilation profile called `maxperf` which enables more aggressive compiler optimisations at the expense of compilation time.

Some rough initial benchmarks show that this can provide up to a 25% reduction to run time for CPU bound tasks like block processing: https://docs.google.com/spreadsheets/d/15jHuZe7lLHhZq9Nw8kc6EL0Qh_N_YAYqkW2NQ_Afmtk/edit

The numbers in that spreadsheet compare the `consensus-context` branch from #3604 to the same branch compiled with the `maxperf` profile using:

```
PROFILE=maxperf make install-lcli
```

## Additional Info

The downsides of the maxperf profile are:

- It increases compile times substantially, which will particularly impact low-spec hardware. Compiling `lcli` is about 3x slower. Compiling Lighthouse is about 5x slower on my 5950X: 17m 38s rather than 3m 28s.

As a result I think we should not enable this everywhere by default.

- **Option 1**: enable by default for our released binaries. This gives the majority of users the fastest version of `lighthouse` possible, at the expense of slowing down our release CI. Source builds will continue to use the default `release` profile unless users opt-in to `maxperf`.
- **Option 2**: enable by default for source builds. This gives users building from source an edge, but makes them pay for it with compilation time. 

I think I would prefer Option 1. I'll try doing some benchmarking to see how long a maxperf build of Lighthouse would take on GitHub actions.

Credit to Nicholas Nethercote for documenting these options in the Rust Performance Book: https://nnethercote.github.io/perf-book/build-configuration.html.

.github/workflows/docker.yml

@@ -51,6 +51,9 @@ jobs:
                          aarch64-portable,
                          x86_64,
                          x86_64-portable]
+                include:
+                    - profile: maxperf
+
         needs: [extract-version]
         env:
             # We need to enable experimental docker features in order to use `docker buildx`
@@ -67,17 +70,17 @@ jobs:
             - name: Cross build Lighthouse binary
               run: |
                   cargo install cross
-                  make build-${{ matrix.binary }}
+                  env CROSS_PROFILE=${{ matrix.profile }} make build-${{ matrix.binary }}
             - name: Move cross-built binary into Docker scope (if ARM)
               if: startsWith(matrix.binary, 'aarch64')
               run: |
                   mkdir ./bin;
-                  mv ./target/aarch64-unknown-linux-gnu/release/lighthouse ./bin;
+                  mv ./target/aarch64-unknown-linux-gnu/${{ matrix.profile }}/lighthouse ./bin;
             - name: Move cross-built binary into Docker scope (if x86_64)
               if: startsWith(matrix.binary, 'x86_64')
               run: |
                   mkdir ./bin;
-                  mv ./target/x86_64-unknown-linux-gnu/release/lighthouse ./bin;
+                  mv ./target/x86_64-unknown-linux-gnu/${{ matrix.profile }}/lighthouse ./bin;
             - name: Map aarch64 to arm64 short arch
               if: startsWith(matrix.binary, 'aarch64')
               run: echo "SHORT_ARCH=arm64" >> $GITHUB_ENV