Add optional support for AEGIS encryption

AEGIS is a new family of authenticated encryption algorithms that offers
stronger security, higher usage limits, and better performance than AES-GCM.

This pull request adds support for a new `-aegis` command-line flag, allowing
AEGIS-128X2 to be used as an alternative to AES-GCM on CPUs with AES acceleration.

It also introduces the ability to use ciphers with different key sizes.

More information on AEGIS is available here:
- https://cfrg.github.io/draft-irtf-cfrg-aegis-aead/draft-irtf-cfrg-aegis-aead.html
- https://github.com/cfrg/draft-irtf-cfrg-aegis-aead

gocryptfs -speed speed on Apple M1:

AES-GCM-256-OpenSSL              3718.79 MB/s
AES-GCM-256-Go                   5083.43 MB/s   (selected in auto mode)
AES-SIV-512-Go                    625.20 MB/s
XChaCha20-Poly1305-OpenSSL       1358.63 MB/s   (selected in auto mode)
XChaCha20-Poly1305-Go             832.11 MB/s
Aegis128X2-Go                   11818.73 MB/s

gocryptfs -speed speed on AMD Zen 4:

AES-GCM-256-OpenSSL              5215.86 MB/s
AES-GCM-256-Go                   6918.01 MB/s   (selected in auto mode)
AES-SIV-512-Go                    449.61 MB/s
XChaCha20-Poly1305-OpenSSL       2643.48 MB/s
XChaCha20-Poly1305-Go            3727.46 MB/s   (selected in auto mode)
Aegis128X2-Go                   28109.92 MB/s

1 files changed, 1 insertions, 1 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c29194a..60f4f76 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,7 +47,7 @@ jobs:
     - run: echo -e 'user_allow_other\nmount_max = 10000' | sudo tee -a /etc/fuse.conf && cat /etc/fuse.conf
 
     # Build & upload static binary
-    - run: ./build-without-openssl.bash
+    - run: ./build-without-cgo.bash
     - uses: actions/upload-artifact@v4
       with:
         name: gocryptfs ${{ github.sha }} static ${{ runner.arch }} binary, Go ${{ matrix.go }}