apm-server binary is not statically linked

[kruskall]

APM Server version (apm-server version): 772db00

Description of the problem including expected versus actual behavior:

Building apm-server produces a dynamically linked binary. This makes it impossible to run in minimal environment (distroless, alpine, chainguard, etc.).

Steps to reproduce:

1. make apm-server
2. file apm-server

Provide logs (if relevant):

[kruskall]

fwiw removing -buildmode=pie produces a statically linked binary